Code:
/ Dotnetfx_Vista_SP2 / Dotnetfx_Vista_SP2 / 8.0.50727.4016 / DEVDIV / depot / DevDiv / releases / Orcas / QFE / wpf / src / Framework / System / Windows / Data / MultiBindingExpression.cs / 1 / MultiBindingExpression.cs
//----------------------------------------------------------------------------
//
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
//
// Description: Defines MultiBindingExpression object, uses a collection of BindingExpressions together.
//
// See spec at http://avalon/connecteddata/Specs/Data%20Binding.mht
//
//---------------------------------------------------------------------------
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Globalization;
using System.Windows.Threading;
using System.Threading;
using System.Windows.Controls;
using System.Windows.Input; // FocusChangedEvent
using System.Windows.Markup;
using MS.Internal.Controls; // Validation
using MS.Internal.KnownBoxes;
using MS.Internal.Data;
using MS.Utility;
using MS.Internal; // Invariant.Assert
namespace System.Windows.Data
{
///
/// Describes a collection of BindingExpressions attached to a single property.
/// The inner BindingExpressions contribute their values to the MultiBindingExpression,
/// which combines/converts them into a resultant final value.
/// In the reverse direction, the target value is tranlated to
/// a set of values that are fed back into the inner BindingExpressions.
///
public sealed class MultiBindingExpression: BindingExpressionBase, IDataBindEngineClient
{
//-----------------------------------------------------
//
// Constructors
//
//-----------------------------------------------------
/// Constructor
private MultiBindingExpression(MultiBinding binding, BindingExpressionBase owner)
: base(binding, owner)
{
int count = binding.Bindings.Count;
// reduce repeated allocations
_tempValues = new object[count];
_tempTypes = new Type[count];
}
//------------------------------------------------------
//
// Interfaces
//
//-----------------------------------------------------
void IDataBindEngineClient.TransferValue()
{
TransferValue();
}
void IDataBindEngineClient.UpdateValue()
{
UpdateValue();
}
bool IDataBindEngineClient.AttachToContext(bool lastChance)
{
AttachToContext(lastChance);
return !TransferIsDeferred;
}
void IDataBindEngineClient.OnTargetUpdated()
{
OnTargetUpdated();
}
DependencyObject IDataBindEngineClient.TargetElement
{
get { return TargetElement; }
}
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
/// Binding from which this expression was created
public MultiBinding ParentMultiBinding { get { return (MultiBinding)ParentBindingBase; } }
/// List of inner BindingExpression
public ReadOnlyCollection BindingExpressions
{
get { return new ReadOnlyCollection(MutableBindingExpressions); }
}
//-----------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
/// Send the current value back to the source(s)
/// Does nothing when binding's Mode is not TwoWay or OneWayToSource
public override void UpdateSource()
{
// ultimately, what would be better would be to have a status flag that
// indicates that this MultiBindingExpression has been Detached, as opposed to a
// MultiBindingExpression that doesn't have anything in its BindingExpressions collection
// in the first place. Added to which, there should be distinct error
// messages for both of these error conditions.
if (MutableBindingExpressions.Count == 0)
throw new InvalidOperationException(SR.Get(SRID.BindingExpressionIsDetached));
NeedsUpdate = true; // force update
Update(true); // update synchronously
}
/// Force a data transfer from sources to target
/// Will transfer data even if binding's Mode is OneWay
public override void UpdateTarget()
{
// ultimately, what would be better would be to have a status flag that
// indicates that this MultiBindingExpression has been Detached, as opposed to a
// MultiBindingExpression that doesn't have anything in its BindingExpressions collection
// in the first place. Added to which, there should be distinct error
// messages for both of these error conditions.
if (MutableBindingExpressions.Count == 0)
throw new InvalidOperationException(SR.Get(SRID.BindingExpressionIsDetached));
UpdateTarget(true);
}
#region Expression overrides
///
/// Called to evaluate the Expression value
///
/// DependencyObject being queried
/// Property being queried
/// Computed value. Unset if unavailable.
internal override object GetValue(DependencyObject d, DependencyProperty dp)
{
return Value;
}
///
/// Allows Expression to store set values
///
/// DependencyObject being set
/// Property being set
/// Value being set
/// true if Expression handled storing of the value
internal override bool SetValue(DependencyObject d, DependencyProperty dp, object value)
{
if (IsReflective)
{
Value = value;
return true;
}
else
{
// if the binding doesn't push values back to the source, allow
// SetValue to overwrite the binding with a local value
return false;
}
}
///
/// Notification that a Dependent that this Expression established has
/// been invalidated as a result of a Source invalidation
///
/// DependencyObject that was invalidated
/// Changed event args for the property that was invalidated
internal override void OnPropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
{
// If this method is changed to use d or dp directly, uncomment these lines
//if (d == null)
// throw new ArgumentNullException(d);
//if (dp == null)
// throw new ArgumentNullException(dp);
// if the notification arrived on the right Dispatcher, handle it now.
if (Dispatcher.Thread == Thread.CurrentThread)
{
HandlePropertyInvalidation(d, args);
}
else // Otherwise, marshal it to the right Dispatcher.
{
Dispatcher.BeginInvoke(
DispatcherPriority.DataBind,
new DispatcherOperationCallback(HandlePropertyInvalidationOperation),
new object[]{d, args});
}
}
#endregion Expression overrides
//-----------------------------------------------------
//
// Internal Properties
//
//-----------------------------------------------------
internal override bool IsParentBindingUpdateTriggerDefault
{
get { return (ParentMultiBinding.UpdateSourceTrigger == UpdateSourceTrigger.Default); }
}
//-----------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
// Create a new BindingExpression from the given Binding description
internal static MultiBindingExpression CreateBindingExpression(DependencyObject d, DependencyProperty dp, MultiBinding binding, BindingExpressionBase owner)
{
FrameworkPropertyMetadata fwMetaData = dp.GetMetadata(d.DependencyObjectType) as FrameworkPropertyMetadata;
if ((fwMetaData != null && !fwMetaData.IsDataBindingAllowed) || dp.ReadOnly)
throw new ArgumentException(SR.Get(SRID.PropertyNotBindable, dp.Name), "dp");
// create the BindingExpression
MultiBindingExpression bindExpr = new MultiBindingExpression(binding, owner);
// prevert transfers and updates until multiBindingExpression is ready
bindExpr.IsInTransfer = true;
bindExpr.IsInUpdate = true;
bindExpr.ResolvePropertyDefaultSettings(binding.Mode, binding.UpdateSourceTrigger, fwMetaData);
return bindExpr;
}
// Attach to things that may require tree context (parent, root, etc.)
void AttachToContext(bool lastChance)
{
DependencyObject target = TargetElement;
if (target == null)
return;
Debug.Assert(ParentMultiBinding.Converter != null || !String.IsNullOrEmpty(EffectiveStringFormat),
"MultiBindingExpression should not exist if its bind does not have a valid converter.");
bool isExtendedTraceEnabled = TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.AttachToContext);
_converter = ParentMultiBinding.Converter;
if (_converter == null && String.IsNullOrEmpty(EffectiveStringFormat))
{
TraceData.Trace(TraceEventType.Error, TraceData.MultiBindingHasNoConverter, ParentMultiBinding);
}
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.AttachToContext(
TraceData.Identify(this),
lastChance ? " (last chance)" : String.Empty));
}
TransferIsDeferred = true;
bool attached = true; // true if all child bindings have attached
int count = MutableBindingExpressions.Count;
for (int i = 0; i < count; ++i)
{
if (MutableBindingExpressions[i].Status == BindingStatus.Unattached)
attached = false;
}
// if the child bindings aren't ready yet, try again later. Leave
// TransferIsDeferred set, to indicate we're not ready yet.
if (!attached && !lastChance)
{
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.ChildNotAttached(
TraceData.Identify(this)));
}
return;
}
// initial transfer
TransferIsDeferred = false;
EndSourceUpdate(); // now the MultiBindingExpression is ready for Transfers
SetStatus(BindingStatus.Active);
if (!IsOneWayToSource)
{
UpdateTarget(false);
}
else
{
IsInTransfer = false; // set at creation time
UpdateValue();
}
}
//-----------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
///
/// The ValidationError that caused this
/// BindingExpression to be invalid.
///
public override ValidationError ValidationError
{
get
{
ValidationError validationError = base.ValidationError;
if (validationError == null)
{
for ( int i = 0; i < MutableBindingExpressions.Count; i++ )
{
validationError = MutableBindingExpressions[i].ValidationError;
if (validationError != null)
break;
}
}
return validationError;
}
}
///
/// HasError returns true if any of the ValidationRules
/// of any of its inner bindings failed its validation rule
/// or the Multi-/PriorityBinding itself has a failing validation rule.
///
public override bool HasError
{
get
{
bool hasError = base.HasError;
if (!hasError)
{
for ( int i = 0; i < MutableBindingExpressions.Count; i++ )
{
if (MutableBindingExpressions[i].HasError)
return true;
}
}
return hasError;
}
}
//------------------------------------------------------
//
// Protected Internal Methods
//
//-----------------------------------------------------
///
/// Attach a BindingExpression to the given target (element, property)
///
/// DependencyObject being set
/// Property being set
internal override void AttachOverride(DependencyObject d, DependencyProperty dp)
{
base.AttachOverride(d, dp);
DependencyObject target = TargetElement;
if (target == null)
return;
// listen for lost focus
if (IsUpdateOnLostFocus)
{
LostFocusEventManager.AddListener(target, this);
}
TransferIsDeferred = true; // Defer data transfer until after we activate all the BindingExpressions
int count = ParentMultiBinding.Bindings.Count;
for (int i = 0; i < count; ++i)
{
// ISSUE: It may be possible to have _attachedBindingExpressions be non-zero
// at the end of Detach if the conditions for the increment on Attach
// and the decrement on Detach are not precisely the same.
AttachBindingExpression(i, false); // create new binding and have it added to end
}
// attach to things that need tree context. Do it synchronously
// if possible, otherwise post a task. This gives the parser et al.
// a chance to assemble the tree before we start walking it.
AttachToContext(false /* lastChance */);
if (TransferIsDeferred)
{
Engine.AddTask(this, TaskOps.AttachToContext);
if (TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.AttachToContext))
{
TraceData.Trace(TraceEventType.Warning,
TraceData.DeferAttachToContext(
TraceData.Identify(this)));
}
}
}
/// sever all connections
internal override void DetachOverride()
{
if (IsUpdateOnLostFocus)
{
LostFocusEventManager.RemoveListener(TargetElement, this);
}
// Theoretically, we only need to detach number of AttentiveBindingExpressions,
// but we'll traverse the whole list anyway and do aggressive clean-up.
int count = MutableBindingExpressions.Count;
for (int i = count - 1; i >= 0; i--)
{
BindingExpressionBase b = MutableBindingExpressions[i];
if (b != null)
{
b.Detach();
MutableBindingExpressions.RemoveAt(i);
}
}
ChangeSources(null);
base.DetachOverride();
}
///
/// Invalidate the given child expression.
///
internal override void InvalidateChild(BindingExpressionBase bindingExpression)
{
int index = MutableBindingExpressions.IndexOf(bindingExpression);
// do a sanity check that we care about this BindingExpression
if (0 <= index && IsDynamic)
{
NeedsDataTransfer = true;
Transfer(); // this will Invalidate target property.
}
}
///
/// Change the dependency sources for the given child expression.
///
internal override void ChangeSourcesForChild(BindingExpressionBase bindingExpression, WeakDependencySource[] newSources)
{
int index = MutableBindingExpressions.IndexOf(bindingExpression);
if (index >= 0)
{
WeakDependencySource[] combinedSources = CombineSources(index, MutableBindingExpressions, MutableBindingExpressions.Count, newSources);
ChangeSources(combinedSources);
}
}
///
/// Replace the given child expression with a new one.
///
internal override void ReplaceChild(BindingExpressionBase bindingExpression)
{
int index = MutableBindingExpressions.IndexOf(bindingExpression);
DependencyObject target = TargetElement;
if (index >= 0 && target != null)
{
// detach and clean up the old binding
bindingExpression.Detach();
// replace BindingExpression
AttachBindingExpression(index, true);
}
}
// register the leaf bindings with the binding group
internal override void UpdateBindingGroup(BindingGroup bg)
{
for (int i=0, n=MutableBindingExpressions.Count-1; i
/// Get the converted proposed value
///
internal override object ConvertProposedValue(object value)
{
DependencyObject target = TargetElement;
if (target == null)
return DependencyProperty.UnsetValue;
if (Converter == null)
{
if (TraceData.IsEnabled)
{
TraceData.Trace(TraceEventType.Error, TraceData.MultiValueConverterMissingForUpdate, this);
}
SetStatus(BindingStatus.UpdateSourceError);
return DependencyProperty.UnsetValue;
}
CultureInfo culture = GetCulture();
int count = MutableBindingExpressions.Count;
object[] values = null;
Exception exception = null;
for (int i = 0; i < count; ++i)
{
BindingExpressionBase bindExpr = MutableBindingExpressions[i];
BindingExpression be = bindExpr as BindingExpression;
if (be != null && be.UseDefaultValueConverter)
_tempTypes[i] = be.ConverterSourceType;
else
_tempTypes[i] = TargetProperty.PropertyType;
}
// MultiValueConverters are always user-defined, so don't catch exceptions (bug 992237)
values = Converter.ConvertBack(value, _tempTypes, ParentMultiBinding.ConverterParameter, culture);
if (values == null)
{
if (TraceData.IsEnabled)
{
TraceData.Trace(TraceEventType.Error,
TraceData.BadMultiConverterForUpdate(
Converter.GetType().Name,
AvTrace.ToStringHelper(value),
AvTrace.TypeName(value)),
this, exception);
}
return DependencyProperty.UnsetValue;
}
if (TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.Update))
{
for (int i=0; i
/// Get the converted proposed value and inform the binding group
///
internal override void ObtainConvertedProposedValue(BindingGroup bindingGroup)
{
if (NeedsUpdate)
{
object value = bindingGroup.GetValue(this);
if (value != DependencyProperty.UnsetValue)
{
value = ConvertProposedValue(value);
}
StoreValueInBindingGroup(value, bindingGroup);
}
else
{
bindingGroup.UseSourceValue(this);
}
}
///
/// Update the source value
///
internal override object UpdateSource(object convertedValue)
{
if (convertedValue == DependencyProperty.UnsetValue)
return convertedValue;
object[] values = convertedValue as object[];
int count = MutableBindingExpressions.Count;
if (values.Length < count)
count = values.Length;
BeginSourceUpdate();
for (int i = 0; i < count; ++i)
{
object value = values[i];
if (value != Binding.DoNothing && value != DependencyProperty.UnsetValue)
{
BindingExpressionBase bindExpr = MutableBindingExpressions[i];
bindExpr.UpdateSource(value);
}
}
EndSourceUpdate();
OnSourceUpdated();
return convertedValue;
}
///
/// Update the source value and inform the binding group
///
internal override void UpdateSource(BindingGroup bindingGroup)
{
if (NeedsUpdate)
{
object value = bindingGroup.GetValue(this);
UpdateSource(value);
}
}
///
/// Store the value in the binding group
///
internal override void StoreValueInBindingGroup(object value, BindingGroup bindingGroup)
{
bindingGroup.SetValue(this, value);
object[] values = value as object[];
if (values != null)
{
int count = MutableBindingExpressions.Count;
if (values.Length < count)
count = values.Length;
for (int i=0; i=0; --i)
{
MutableBindingExpressions[i].StoreValueInBindingGroup(DependencyProperty.UnsetValue, bindingGroup);
}
}
}
///
/// Run validation rules for the given step
///
internal override bool Validate(object value, ValidationStep validationStep)
{
if (value == Binding.DoNothing || value == DependencyProperty.UnsetValue)
return true;
// run rules attached to this multibinding
bool result = base.Validate(value, validationStep);
// run rules attached to the child bindings
switch (validationStep)
{
case ValidationStep.RawProposedValue:
// the child bindings don't get raw values until the Convert step
break;
default:
object[] values = value as object[];
int count = MutableBindingExpressions.Count;
if (values.Length < count)
count = values.Length;
for (int i=0; i
/// Run validation rules for the given step, and inform the binding group
///
internal override bool CheckValidationRules(BindingGroup bindingGroup, ValidationStep validationStep)
{
if (!NeedsValidation)
return true;
object value;
switch (validationStep)
{
case ValidationStep.RawProposedValue:
case ValidationStep.ConvertedProposedValue:
case ValidationStep.UpdatedValue:
case ValidationStep.CommittedValue:
value = bindingGroup.GetValue(this);
break;
default:
throw new InvalidOperationException(SR.Get(SRID.ValidationRule_UnknownStep, validationStep, bindingGroup));
}
bool result = Validate(value, validationStep);
if (result && validationStep == ValidationStep.CommittedValue)
{
NeedsValidation = false;
}
return result;
}
//------------------------------------------------------
//
// Private Properties
//
//-----------------------------------------------------
///
/// expose a mutable version of the list of all BindingExpressions;
/// derived internal classes need to be able to populate this list
///
private Collection MutableBindingExpressions
{
get { return _list; }
}
IMultiValueConverter Converter
{
get { return _converter; }
set { _converter = value; }
}
//-----------------------------------------------------
//
// Private Methods
//
//-----------------------------------------------------
// Create a BindingExpression for position i
BindingExpressionBase AttachBindingExpression(int i, bool replaceExisting)
{
DependencyObject target = TargetElement;
if (target == null)
return null;
BindingBase binding = ParentMultiBinding.Bindings[i];
// Check if replacement bindings have the correct UpdateSourceTrigger
MultiBinding.CheckTrigger(binding);
BindingExpressionBase bindExpr = binding.CreateBindingExpression(target, TargetProperty, this);
if (replaceExisting) // replace exisiting or add as new binding?
MutableBindingExpressions[i] = bindExpr;
else
MutableBindingExpressions.Add(bindExpr);
bindExpr.Attach(target, TargetProperty);
return bindExpr;
}
private object HandlePropertyInvalidationOperation(object o)
{
// This is the case where the source of the Binding belonged to a different Dispatcher
// than the target. For this scenario the source marshals off the invalidation information
// onto the target's Dispatcher queue. This is where we unpack the marshalled information
// to fire the invalidation on the target object.
object[] args = (object[])o;
HandlePropertyInvalidation((DependencyObject)args[0], (DependencyPropertyChangedEventArgs)args[1]);
return null;
}
private void HandlePropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
{
DependencyProperty dp = args.Property;
int n = MutableBindingExpressions.Count;
if (TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.Events))
{
TraceData.Trace(TraceEventType.Warning,
TraceData.GotPropertyChanged(
TraceData.Identify(this),
TraceData.Identify(d),
dp.Name));
}
TransferIsDeferred = true;
for (int i = 0; i < n; ++i)
{
BindingExpressionBase bindExpr = MutableBindingExpressions[i];
if (bindExpr != null)
{
DependencySource[] sources = bindExpr.GetSources();
if (sources != null)
{
for (int j = 0; j < sources.Length; ++j)
{
DependencySource source = sources[j];
if (source.DependencyObject == d && source.DependencyProperty == dp)
{
bindExpr.OnPropertyInvalidation(d, args);
break;
}
}
}
}
}
TransferIsDeferred = false;
Transfer(); // Transfer if inner BindingExpressions have called Invalidate(binding)
}
// invalidate the target property
void Invalidate()
{
// don't invalidate during Attach. The property engine does it
// already, and it would interfere with the on-demand activation
// of style-defined BindingExpressions.
if (IsAttaching)
return;
DependencyObject target = TargetElement;
if (target != null)
{
// recompute expression
target.InvalidateProperty(TargetProperty);
}
}
///
/// Handle events from the centralized event table
///
internal override bool ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
{
if (TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.Events))
{
TraceData.Trace(TraceEventType.Warning,
TraceData.GotEvent(
TraceData.Identify(this),
TraceData.IdentifyWeakEvent(managerType),
TraceData.Identify(sender)));
}
if (managerType == typeof(LostFocusEventManager))
{
Update(true);
}
else
{
return base.ReceiveWeakEvent(managerType, sender, e);
}
return true;
}
#region Value
/// Force a data transfer from source(s) to target
///
/// use true to propagate UpdateTarget call to all inner BindingExpressions;
/// use false to avoid forcing data re-transfer from one-time inner BindingExpressions
///
void UpdateTarget(bool includeInnerBindings)
{
TransferIsDeferred = true;
if (includeInnerBindings)
{
foreach (BindingExpressionBase b in MutableBindingExpressions)
{
b.UpdateTarget();
}
}
TransferIsDeferred = false;
NeedsDataTransfer = true; // force data transfer
Transfer();
}
// transfer a value from the source to the target
void Transfer()
{
// required state for transfer
if ( NeedsDataTransfer // Transfer is needed
&& !IsInUpdate // Not in an update
&& !TransferIsDeferred) // Not aggregating transfers
{
TransferValue();
}
}
// transfer a value from the source to the target
void TransferValue()
{
IsInTransfer = true;
NeedsDataTransfer = false;
DependencyObject target = TargetElement;
if (target == null)
goto Done;
bool isExtendedTraceEnabled = TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.Transfer);
object value = DependencyProperty.UnsetValue;
object preFormattedValue = _tempValues;
CultureInfo culture = GetCulture();
// gather values from inner BindingExpressions
int count = MutableBindingExpressions.Count;
for (int i = 0; i < count; ++i)
{
_tempValues[i] = MutableBindingExpressions[i].GetValue(target, TargetProperty); // could pass (null, null)
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.GetRawValueMulti(
TraceData.Identify(this),
i,
TraceData.Identify(_tempValues[i])));
}
}
// apply the converter
if (Converter != null)
{
// MultiValueConverters are always user-defined, so don't catch exceptions (bug 992237)
preFormattedValue = Converter.Convert(_tempValues, TargetProperty.PropertyType, ParentMultiBinding.ConverterParameter, culture);
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.UserConverter(
TraceData.Identify(this),
TraceData.Identify(preFormattedValue)));
}
}
else if (EffectiveStringFormat != null)
{
// preFormattedValue = _tempValues;
}
else // no converter (perhaps user specified it in error)
{
if (TraceData.IsEnabled)
{
TraceData.Trace(TraceEventType.Error, TraceData.MultiValueConverterMissingForTransfer, this);
}
goto Done;
}
// apply string formatting
if (EffectiveStringFormat == null || preFormattedValue == Binding.DoNothing || preFormattedValue == DependencyProperty.UnsetValue)
{
value = preFormattedValue;
}
else
{
try
{
// we call String.Format either with multiple values (obtained from
// the child bindings) or a single value (as produced by the converter).
// The if-test is needed to avoid wrapping _tempValues inside another object[].
if (preFormattedValue == _tempValues)
{
value = String.Format(culture, EffectiveStringFormat, _tempValues);
}
else
{
value = String.Format(culture, EffectiveStringFormat, preFormattedValue);
}
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.FormattedValue(
TraceData.Identify(this),
TraceData.Identify(value)));
}
}
catch (FormatException)
{
// formatting didn't work
value = DependencyProperty.UnsetValue;
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.FormattingFailed(
TraceData.Identify(this),
EffectiveStringFormat));
}
}
}
Array.Clear(_tempValues, 0, _tempValues.Length);
// the special value DoNothing means no error, but no data transfer
if (value == Binding.DoNothing)
goto Done;
// ultimately, TargetNullValue should get assigned implicitly,
// even if the user doesn't declare it. We can't do this yet because
// of back-compat. I wrote it both ways, and #if'd out the breaking
// change.
#if TargetNullValueBC //BreakingChange
if (IsNullValue(value))
#else
if (EffectiveTargetNullValue != DependencyProperty.UnsetValue &&
IsNullValue(value))
#endif
{
value = EffectiveTargetNullValue;
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.NullConverter(
TraceData.Identify(this),
TraceData.Identify(value)));
}
}
// if the value isn't acceptable to the target property, don't use it
if (value != DependencyProperty.UnsetValue && !TargetProperty.IsValidValue(value))
{
if (TraceData.IsEnabled)
{
TraceData.Trace(TraceLevel, TraceData.BadValueAtTransfer, value, this);
}
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.BadValueAtTransferExtended(
TraceData.Identify(this),
TraceData.Identify(value)));
}
value = DependencyProperty.UnsetValue;
}
// if we can't obtain a value, try the fallback value.
if (value == DependencyProperty.UnsetValue)
{
value = UseFallbackValue();
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.UseFallback(
TraceData.Identify(this),
TraceData.Identify(value)));
}
}
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.TransferValue(
TraceData.Identify(this),
TraceData.Identify(value)));
}
// update the cached value
ChangeValue(value, true);
Invalidate();
OnTargetUpdated();
Validation.ClearInvalid(this);
Done:
IsInTransfer = false;
}
void OnTargetUpdated()
{
if (NotifyOnTargetUpdated)
{
DependencyObject target = TargetElement;
if (target != null)
{
// while attaching a normal (not style-defined) BindingExpression,
// we must defer raising the event until after the
// property has been invalidated, so that the event handler
// gets the right value if it asks (bug 1036862)
if (IsAttaching && this == target.ReadLocalValue(TargetProperty))
{
Engine.AddTask(this, TaskOps.RaiseTargetUpdatedEvent);
}
else
{
BindingExpression.OnTargetUpdated(target, TargetProperty);
}
}
}
}
void OnSourceUpdated()
{
if (NotifyOnSourceUpdated)
{
DependencyObject target = TargetElement;
if (target != null)
{
BindingExpression.OnSourceUpdated(target, TargetProperty);
}
}
}
// transfer a value from the target to the source
internal override void Update(bool synchronous)
{
// various reasons not to update:
if ( !NeedsUpdate // nothing to do
|| !IsReflective // no update desired
|| IsInTransfer // in a transfer
)
return;
if (synchronous)
{
UpdateValue();
}
else
{
Engine.AddTask(this, TaskOps.UpdateValue);
}
}
#endregion Value
//------------------------------------------------------
//
// Private Fields
//
//-----------------------------------------------------
Collection _list = new Collection();
IMultiValueConverter _converter;
object[] _tempValues;
Type[] _tempTypes;
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
//----------------------------------------------------------------------------
//
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
//
// Description: Defines MultiBindingExpression object, uses a collection of BindingExpressions together.
//
// See spec at http://avalon/connecteddata/Specs/Data%20Binding.mht
//
//---------------------------------------------------------------------------
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Globalization;
using System.Windows.Threading;
using System.Threading;
using System.Windows.Controls;
using System.Windows.Input; // FocusChangedEvent
using System.Windows.Markup;
using MS.Internal.Controls; // Validation
using MS.Internal.KnownBoxes;
using MS.Internal.Data;
using MS.Utility;
using MS.Internal; // Invariant.Assert
namespace System.Windows.Data
{
///
/// Describes a collection of BindingExpressions attached to a single property.
/// The inner BindingExpressions contribute their values to the MultiBindingExpression,
/// which combines/converts them into a resultant final value.
/// In the reverse direction, the target value is tranlated to
/// a set of values that are fed back into the inner BindingExpressions.
///
public sealed class MultiBindingExpression: BindingExpressionBase, IDataBindEngineClient
{
//-----------------------------------------------------
//
// Constructors
//
//-----------------------------------------------------
/// Constructor
private MultiBindingExpression(MultiBinding binding, BindingExpressionBase owner)
: base(binding, owner)
{
int count = binding.Bindings.Count;
// reduce repeated allocations
_tempValues = new object[count];
_tempTypes = new Type[count];
}
//------------------------------------------------------
//
// Interfaces
//
//-----------------------------------------------------
void IDataBindEngineClient.TransferValue()
{
TransferValue();
}
void IDataBindEngineClient.UpdateValue()
{
UpdateValue();
}
bool IDataBindEngineClient.AttachToContext(bool lastChance)
{
AttachToContext(lastChance);
return !TransferIsDeferred;
}
void IDataBindEngineClient.OnTargetUpdated()
{
OnTargetUpdated();
}
DependencyObject IDataBindEngineClient.TargetElement
{
get { return TargetElement; }
}
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
/// Binding from which this expression was created
public MultiBinding ParentMultiBinding { get { return (MultiBinding)ParentBindingBase; } }
/// List of inner BindingExpression
public ReadOnlyCollection BindingExpressions
{
get { return new ReadOnlyCollection(MutableBindingExpressions); }
}
//-----------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
/// Send the current value back to the source(s)
/// Does nothing when binding's Mode is not TwoWay or OneWayToSource
public override void UpdateSource()
{
// ultimately, what would be better would be to have a status flag that
// indicates that this MultiBindingExpression has been Detached, as opposed to a
// MultiBindingExpression that doesn't have anything in its BindingExpressions collection
// in the first place. Added to which, there should be distinct error
// messages for both of these error conditions.
if (MutableBindingExpressions.Count == 0)
throw new InvalidOperationException(SR.Get(SRID.BindingExpressionIsDetached));
NeedsUpdate = true; // force update
Update(true); // update synchronously
}
/// Force a data transfer from sources to target
/// Will transfer data even if binding's Mode is OneWay
public override void UpdateTarget()
{
// ultimately, what would be better would be to have a status flag that
// indicates that this MultiBindingExpression has been Detached, as opposed to a
// MultiBindingExpression that doesn't have anything in its BindingExpressions collection
// in the first place. Added to which, there should be distinct error
// messages for both of these error conditions.
if (MutableBindingExpressions.Count == 0)
throw new InvalidOperationException(SR.Get(SRID.BindingExpressionIsDetached));
UpdateTarget(true);
}
#region Expression overrides
///
/// Called to evaluate the Expression value
///
/// DependencyObject being queried
/// Property being queried
/// Computed value. Unset if unavailable.
internal override object GetValue(DependencyObject d, DependencyProperty dp)
{
return Value;
}
///
/// Allows Expression to store set values
///
/// DependencyObject being set
/// Property being set
/// Value being set
/// true if Expression handled storing of the value
internal override bool SetValue(DependencyObject d, DependencyProperty dp, object value)
{
if (IsReflective)
{
Value = value;
return true;
}
else
{
// if the binding doesn't push values back to the source, allow
// SetValue to overwrite the binding with a local value
return false;
}
}
///
/// Notification that a Dependent that this Expression established has
/// been invalidated as a result of a Source invalidation
///
/// DependencyObject that was invalidated
/// Changed event args for the property that was invalidated
internal override void OnPropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
{
// If this method is changed to use d or dp directly, uncomment these lines
//if (d == null)
// throw new ArgumentNullException(d);
//if (dp == null)
// throw new ArgumentNullException(dp);
// if the notification arrived on the right Dispatcher, handle it now.
if (Dispatcher.Thread == Thread.CurrentThread)
{
HandlePropertyInvalidation(d, args);
}
else // Otherwise, marshal it to the right Dispatcher.
{
Dispatcher.BeginInvoke(
DispatcherPriority.DataBind,
new DispatcherOperationCallback(HandlePropertyInvalidationOperation),
new object[]{d, args});
}
}
#endregion Expression overrides
//-----------------------------------------------------
//
// Internal Properties
//
//-----------------------------------------------------
internal override bool IsParentBindingUpdateTriggerDefault
{
get { return (ParentMultiBinding.UpdateSourceTrigger == UpdateSourceTrigger.Default); }
}
//-----------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
// Create a new BindingExpression from the given Binding description
internal static MultiBindingExpression CreateBindingExpression(DependencyObject d, DependencyProperty dp, MultiBinding binding, BindingExpressionBase owner)
{
FrameworkPropertyMetadata fwMetaData = dp.GetMetadata(d.DependencyObjectType) as FrameworkPropertyMetadata;
if ((fwMetaData != null && !fwMetaData.IsDataBindingAllowed) || dp.ReadOnly)
throw new ArgumentException(SR.Get(SRID.PropertyNotBindable, dp.Name), "dp");
// create the BindingExpression
MultiBindingExpression bindExpr = new MultiBindingExpression(binding, owner);
// prevert transfers and updates until multiBindingExpression is ready
bindExpr.IsInTransfer = true;
bindExpr.IsInUpdate = true;
bindExpr.ResolvePropertyDefaultSettings(binding.Mode, binding.UpdateSourceTrigger, fwMetaData);
return bindExpr;
}
// Attach to things that may require tree context (parent, root, etc.)
void AttachToContext(bool lastChance)
{
DependencyObject target = TargetElement;
if (target == null)
return;
Debug.Assert(ParentMultiBinding.Converter != null || !String.IsNullOrEmpty(EffectiveStringFormat),
"MultiBindingExpression should not exist if its bind does not have a valid converter.");
bool isExtendedTraceEnabled = TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.AttachToContext);
_converter = ParentMultiBinding.Converter;
if (_converter == null && String.IsNullOrEmpty(EffectiveStringFormat))
{
TraceData.Trace(TraceEventType.Error, TraceData.MultiBindingHasNoConverter, ParentMultiBinding);
}
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.AttachToContext(
TraceData.Identify(this),
lastChance ? " (last chance)" : String.Empty));
}
TransferIsDeferred = true;
bool attached = true; // true if all child bindings have attached
int count = MutableBindingExpressions.Count;
for (int i = 0; i < count; ++i)
{
if (MutableBindingExpressions[i].Status == BindingStatus.Unattached)
attached = false;
}
// if the child bindings aren't ready yet, try again later. Leave
// TransferIsDeferred set, to indicate we're not ready yet.
if (!attached && !lastChance)
{
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.ChildNotAttached(
TraceData.Identify(this)));
}
return;
}
// initial transfer
TransferIsDeferred = false;
EndSourceUpdate(); // now the MultiBindingExpression is ready for Transfers
SetStatus(BindingStatus.Active);
if (!IsOneWayToSource)
{
UpdateTarget(false);
}
else
{
IsInTransfer = false; // set at creation time
UpdateValue();
}
}
//-----------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
///
/// The ValidationError that caused this
/// BindingExpression to be invalid.
///
public override ValidationError ValidationError
{
get
{
ValidationError validationError = base.ValidationError;
if (validationError == null)
{
for ( int i = 0; i < MutableBindingExpressions.Count; i++ )
{
validationError = MutableBindingExpressions[i].ValidationError;
if (validationError != null)
break;
}
}
return validationError;
}
}
///
/// HasError returns true if any of the ValidationRules
/// of any of its inner bindings failed its validation rule
/// or the Multi-/PriorityBinding itself has a failing validation rule.
///
public override bool HasError
{
get
{
bool hasError = base.HasError;
if (!hasError)
{
for ( int i = 0; i < MutableBindingExpressions.Count; i++ )
{
if (MutableBindingExpressions[i].HasError)
return true;
}
}
return hasError;
}
}
//------------------------------------------------------
//
// Protected Internal Methods
//
//-----------------------------------------------------
///
/// Attach a BindingExpression to the given target (element, property)
///
/// DependencyObject being set
/// Property being set
internal override void AttachOverride(DependencyObject d, DependencyProperty dp)
{
base.AttachOverride(d, dp);
DependencyObject target = TargetElement;
if (target == null)
return;
// listen for lost focus
if (IsUpdateOnLostFocus)
{
LostFocusEventManager.AddListener(target, this);
}
TransferIsDeferred = true; // Defer data transfer until after we activate all the BindingExpressions
int count = ParentMultiBinding.Bindings.Count;
for (int i = 0; i < count; ++i)
{
// ISSUE: It may be possible to have _attachedBindingExpressions be non-zero
// at the end of Detach if the conditions for the increment on Attach
// and the decrement on Detach are not precisely the same.
AttachBindingExpression(i, false); // create new binding and have it added to end
}
// attach to things that need tree context. Do it synchronously
// if possible, otherwise post a task. This gives the parser et al.
// a chance to assemble the tree before we start walking it.
AttachToContext(false /* lastChance */);
if (TransferIsDeferred)
{
Engine.AddTask(this, TaskOps.AttachToContext);
if (TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.AttachToContext))
{
TraceData.Trace(TraceEventType.Warning,
TraceData.DeferAttachToContext(
TraceData.Identify(this)));
}
}
}
/// sever all connections
internal override void DetachOverride()
{
if (IsUpdateOnLostFocus)
{
LostFocusEventManager.RemoveListener(TargetElement, this);
}
// Theoretically, we only need to detach number of AttentiveBindingExpressions,
// but we'll traverse the whole list anyway and do aggressive clean-up.
int count = MutableBindingExpressions.Count;
for (int i = count - 1; i >= 0; i--)
{
BindingExpressionBase b = MutableBindingExpressions[i];
if (b != null)
{
b.Detach();
MutableBindingExpressions.RemoveAt(i);
}
}
ChangeSources(null);
base.DetachOverride();
}
///
/// Invalidate the given child expression.
///
internal override void InvalidateChild(BindingExpressionBase bindingExpression)
{
int index = MutableBindingExpressions.IndexOf(bindingExpression);
// do a sanity check that we care about this BindingExpression
if (0 <= index && IsDynamic)
{
NeedsDataTransfer = true;
Transfer(); // this will Invalidate target property.
}
}
///
/// Change the dependency sources for the given child expression.
///
internal override void ChangeSourcesForChild(BindingExpressionBase bindingExpression, WeakDependencySource[] newSources)
{
int index = MutableBindingExpressions.IndexOf(bindingExpression);
if (index >= 0)
{
WeakDependencySource[] combinedSources = CombineSources(index, MutableBindingExpressions, MutableBindingExpressions.Count, newSources);
ChangeSources(combinedSources);
}
}
///
/// Replace the given child expression with a new one.
///
internal override void ReplaceChild(BindingExpressionBase bindingExpression)
{
int index = MutableBindingExpressions.IndexOf(bindingExpression);
DependencyObject target = TargetElement;
if (index >= 0 && target != null)
{
// detach and clean up the old binding
bindingExpression.Detach();
// replace BindingExpression
AttachBindingExpression(index, true);
}
}
// register the leaf bindings with the binding group
internal override void UpdateBindingGroup(BindingGroup bg)
{
for (int i=0, n=MutableBindingExpressions.Count-1; i
/// Get the converted proposed value
///
internal override object ConvertProposedValue(object value)
{
DependencyObject target = TargetElement;
if (target == null)
return DependencyProperty.UnsetValue;
if (Converter == null)
{
if (TraceData.IsEnabled)
{
TraceData.Trace(TraceEventType.Error, TraceData.MultiValueConverterMissingForUpdate, this);
}
SetStatus(BindingStatus.UpdateSourceError);
return DependencyProperty.UnsetValue;
}
CultureInfo culture = GetCulture();
int count = MutableBindingExpressions.Count;
object[] values = null;
Exception exception = null;
for (int i = 0; i < count; ++i)
{
BindingExpressionBase bindExpr = MutableBindingExpressions[i];
BindingExpression be = bindExpr as BindingExpression;
if (be != null && be.UseDefaultValueConverter)
_tempTypes[i] = be.ConverterSourceType;
else
_tempTypes[i] = TargetProperty.PropertyType;
}
// MultiValueConverters are always user-defined, so don't catch exceptions (bug 992237)
values = Converter.ConvertBack(value, _tempTypes, ParentMultiBinding.ConverterParameter, culture);
if (values == null)
{
if (TraceData.IsEnabled)
{
TraceData.Trace(TraceEventType.Error,
TraceData.BadMultiConverterForUpdate(
Converter.GetType().Name,
AvTrace.ToStringHelper(value),
AvTrace.TypeName(value)),
this, exception);
}
return DependencyProperty.UnsetValue;
}
if (TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.Update))
{
for (int i=0; i
/// Get the converted proposed value and inform the binding group
///
internal override void ObtainConvertedProposedValue(BindingGroup bindingGroup)
{
if (NeedsUpdate)
{
object value = bindingGroup.GetValue(this);
if (value != DependencyProperty.UnsetValue)
{
value = ConvertProposedValue(value);
}
StoreValueInBindingGroup(value, bindingGroup);
}
else
{
bindingGroup.UseSourceValue(this);
}
}
///
/// Update the source value
///
internal override object UpdateSource(object convertedValue)
{
if (convertedValue == DependencyProperty.UnsetValue)
return convertedValue;
object[] values = convertedValue as object[];
int count = MutableBindingExpressions.Count;
if (values.Length < count)
count = values.Length;
BeginSourceUpdate();
for (int i = 0; i < count; ++i)
{
object value = values[i];
if (value != Binding.DoNothing && value != DependencyProperty.UnsetValue)
{
BindingExpressionBase bindExpr = MutableBindingExpressions[i];
bindExpr.UpdateSource(value);
}
}
EndSourceUpdate();
OnSourceUpdated();
return convertedValue;
}
///
/// Update the source value and inform the binding group
///
internal override void UpdateSource(BindingGroup bindingGroup)
{
if (NeedsUpdate)
{
object value = bindingGroup.GetValue(this);
UpdateSource(value);
}
}
///
/// Store the value in the binding group
///
internal override void StoreValueInBindingGroup(object value, BindingGroup bindingGroup)
{
bindingGroup.SetValue(this, value);
object[] values = value as object[];
if (values != null)
{
int count = MutableBindingExpressions.Count;
if (values.Length < count)
count = values.Length;
for (int i=0; i=0; --i)
{
MutableBindingExpressions[i].StoreValueInBindingGroup(DependencyProperty.UnsetValue, bindingGroup);
}
}
}
///
/// Run validation rules for the given step
///
internal override bool Validate(object value, ValidationStep validationStep)
{
if (value == Binding.DoNothing || value == DependencyProperty.UnsetValue)
return true;
// run rules attached to this multibinding
bool result = base.Validate(value, validationStep);
// run rules attached to the child bindings
switch (validationStep)
{
case ValidationStep.RawProposedValue:
// the child bindings don't get raw values until the Convert step
break;
default:
object[] values = value as object[];
int count = MutableBindingExpressions.Count;
if (values.Length < count)
count = values.Length;
for (int i=0; i
/// Run validation rules for the given step, and inform the binding group
///
internal override bool CheckValidationRules(BindingGroup bindingGroup, ValidationStep validationStep)
{
if (!NeedsValidation)
return true;
object value;
switch (validationStep)
{
case ValidationStep.RawProposedValue:
case ValidationStep.ConvertedProposedValue:
case ValidationStep.UpdatedValue:
case ValidationStep.CommittedValue:
value = bindingGroup.GetValue(this);
break;
default:
throw new InvalidOperationException(SR.Get(SRID.ValidationRule_UnknownStep, validationStep, bindingGroup));
}
bool result = Validate(value, validationStep);
if (result && validationStep == ValidationStep.CommittedValue)
{
NeedsValidation = false;
}
return result;
}
//------------------------------------------------------
//
// Private Properties
//
//-----------------------------------------------------
///
/// expose a mutable version of the list of all BindingExpressions;
/// derived internal classes need to be able to populate this list
///
private Collection MutableBindingExpressions
{
get { return _list; }
}
IMultiValueConverter Converter
{
get { return _converter; }
set { _converter = value; }
}
//-----------------------------------------------------
//
// Private Methods
//
//-----------------------------------------------------
// Create a BindingExpression for position i
BindingExpressionBase AttachBindingExpression(int i, bool replaceExisting)
{
DependencyObject target = TargetElement;
if (target == null)
return null;
BindingBase binding = ParentMultiBinding.Bindings[i];
// Check if replacement bindings have the correct UpdateSourceTrigger
MultiBinding.CheckTrigger(binding);
BindingExpressionBase bindExpr = binding.CreateBindingExpression(target, TargetProperty, this);
if (replaceExisting) // replace exisiting or add as new binding?
MutableBindingExpressions[i] = bindExpr;
else
MutableBindingExpressions.Add(bindExpr);
bindExpr.Attach(target, TargetProperty);
return bindExpr;
}
private object HandlePropertyInvalidationOperation(object o)
{
// This is the case where the source of the Binding belonged to a different Dispatcher
// than the target. For this scenario the source marshals off the invalidation information
// onto the target's Dispatcher queue. This is where we unpack the marshalled information
// to fire the invalidation on the target object.
object[] args = (object[])o;
HandlePropertyInvalidation((DependencyObject)args[0], (DependencyPropertyChangedEventArgs)args[1]);
return null;
}
private void HandlePropertyInvalidation(DependencyObject d, DependencyPropertyChangedEventArgs args)
{
DependencyProperty dp = args.Property;
int n = MutableBindingExpressions.Count;
if (TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.Events))
{
TraceData.Trace(TraceEventType.Warning,
TraceData.GotPropertyChanged(
TraceData.Identify(this),
TraceData.Identify(d),
dp.Name));
}
TransferIsDeferred = true;
for (int i = 0; i < n; ++i)
{
BindingExpressionBase bindExpr = MutableBindingExpressions[i];
if (bindExpr != null)
{
DependencySource[] sources = bindExpr.GetSources();
if (sources != null)
{
for (int j = 0; j < sources.Length; ++j)
{
DependencySource source = sources[j];
if (source.DependencyObject == d && source.DependencyProperty == dp)
{
bindExpr.OnPropertyInvalidation(d, args);
break;
}
}
}
}
}
TransferIsDeferred = false;
Transfer(); // Transfer if inner BindingExpressions have called Invalidate(binding)
}
// invalidate the target property
void Invalidate()
{
// don't invalidate during Attach. The property engine does it
// already, and it would interfere with the on-demand activation
// of style-defined BindingExpressions.
if (IsAttaching)
return;
DependencyObject target = TargetElement;
if (target != null)
{
// recompute expression
target.InvalidateProperty(TargetProperty);
}
}
///
/// Handle events from the centralized event table
///
internal override bool ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
{
if (TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.Events))
{
TraceData.Trace(TraceEventType.Warning,
TraceData.GotEvent(
TraceData.Identify(this),
TraceData.IdentifyWeakEvent(managerType),
TraceData.Identify(sender)));
}
if (managerType == typeof(LostFocusEventManager))
{
Update(true);
}
else
{
return base.ReceiveWeakEvent(managerType, sender, e);
}
return true;
}
#region Value
/// Force a data transfer from source(s) to target
///
/// use true to propagate UpdateTarget call to all inner BindingExpressions;
/// use false to avoid forcing data re-transfer from one-time inner BindingExpressions
///
void UpdateTarget(bool includeInnerBindings)
{
TransferIsDeferred = true;
if (includeInnerBindings)
{
foreach (BindingExpressionBase b in MutableBindingExpressions)
{
b.UpdateTarget();
}
}
TransferIsDeferred = false;
NeedsDataTransfer = true; // force data transfer
Transfer();
}
// transfer a value from the source to the target
void Transfer()
{
// required state for transfer
if ( NeedsDataTransfer // Transfer is needed
&& !IsInUpdate // Not in an update
&& !TransferIsDeferred) // Not aggregating transfers
{
TransferValue();
}
}
// transfer a value from the source to the target
void TransferValue()
{
IsInTransfer = true;
NeedsDataTransfer = false;
DependencyObject target = TargetElement;
if (target == null)
goto Done;
bool isExtendedTraceEnabled = TraceData.IsExtendedTraceEnabled(this, TraceDataLevel.Transfer);
object value = DependencyProperty.UnsetValue;
object preFormattedValue = _tempValues;
CultureInfo culture = GetCulture();
// gather values from inner BindingExpressions
int count = MutableBindingExpressions.Count;
for (int i = 0; i < count; ++i)
{
_tempValues[i] = MutableBindingExpressions[i].GetValue(target, TargetProperty); // could pass (null, null)
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.GetRawValueMulti(
TraceData.Identify(this),
i,
TraceData.Identify(_tempValues[i])));
}
}
// apply the converter
if (Converter != null)
{
// MultiValueConverters are always user-defined, so don't catch exceptions (bug 992237)
preFormattedValue = Converter.Convert(_tempValues, TargetProperty.PropertyType, ParentMultiBinding.ConverterParameter, culture);
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.UserConverter(
TraceData.Identify(this),
TraceData.Identify(preFormattedValue)));
}
}
else if (EffectiveStringFormat != null)
{
// preFormattedValue = _tempValues;
}
else // no converter (perhaps user specified it in error)
{
if (TraceData.IsEnabled)
{
TraceData.Trace(TraceEventType.Error, TraceData.MultiValueConverterMissingForTransfer, this);
}
goto Done;
}
// apply string formatting
if (EffectiveStringFormat == null || preFormattedValue == Binding.DoNothing || preFormattedValue == DependencyProperty.UnsetValue)
{
value = preFormattedValue;
}
else
{
try
{
// we call String.Format either with multiple values (obtained from
// the child bindings) or a single value (as produced by the converter).
// The if-test is needed to avoid wrapping _tempValues inside another object[].
if (preFormattedValue == _tempValues)
{
value = String.Format(culture, EffectiveStringFormat, _tempValues);
}
else
{
value = String.Format(culture, EffectiveStringFormat, preFormattedValue);
}
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.FormattedValue(
TraceData.Identify(this),
TraceData.Identify(value)));
}
}
catch (FormatException)
{
// formatting didn't work
value = DependencyProperty.UnsetValue;
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.FormattingFailed(
TraceData.Identify(this),
EffectiveStringFormat));
}
}
}
Array.Clear(_tempValues, 0, _tempValues.Length);
// the special value DoNothing means no error, but no data transfer
if (value == Binding.DoNothing)
goto Done;
// ultimately, TargetNullValue should get assigned implicitly,
// even if the user doesn't declare it. We can't do this yet because
// of back-compat. I wrote it both ways, and #if'd out the breaking
// change.
#if TargetNullValueBC //BreakingChange
if (IsNullValue(value))
#else
if (EffectiveTargetNullValue != DependencyProperty.UnsetValue &&
IsNullValue(value))
#endif
{
value = EffectiveTargetNullValue;
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.NullConverter(
TraceData.Identify(this),
TraceData.Identify(value)));
}
}
// if the value isn't acceptable to the target property, don't use it
if (value != DependencyProperty.UnsetValue && !TargetProperty.IsValidValue(value))
{
if (TraceData.IsEnabled)
{
TraceData.Trace(TraceLevel, TraceData.BadValueAtTransfer, value, this);
}
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.BadValueAtTransferExtended(
TraceData.Identify(this),
TraceData.Identify(value)));
}
value = DependencyProperty.UnsetValue;
}
// if we can't obtain a value, try the fallback value.
if (value == DependencyProperty.UnsetValue)
{
value = UseFallbackValue();
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.UseFallback(
TraceData.Identify(this),
TraceData.Identify(value)));
}
}
if (isExtendedTraceEnabled)
{
TraceData.Trace(TraceEventType.Warning,
TraceData.TransferValue(
TraceData.Identify(this),
TraceData.Identify(value)));
}
// update the cached value
ChangeValue(value, true);
Invalidate();
OnTargetUpdated();
Validation.ClearInvalid(this);
Done:
IsInTransfer = false;
}
void OnTargetUpdated()
{
if (NotifyOnTargetUpdated)
{
DependencyObject target = TargetElement;
if (target != null)
{
// while attaching a normal (not style-defined) BindingExpression,
// we must defer raising the event until after the
// property has been invalidated, so that the event handler
// gets the right value if it asks (bug 1036862)
if (IsAttaching && this == target.ReadLocalValue(TargetProperty))
{
Engine.AddTask(this, TaskOps.RaiseTargetUpdatedEvent);
}
else
{
BindingExpression.OnTargetUpdated(target, TargetProperty);
}
}
}
}
void OnSourceUpdated()
{
if (NotifyOnSourceUpdated)
{
DependencyObject target = TargetElement;
if (target != null)
{
BindingExpression.OnSourceUpdated(target, TargetProperty);
}
}
}
// transfer a value from the target to the source
internal override void Update(bool synchronous)
{
// various reasons not to update:
if ( !NeedsUpdate // nothing to do
|| !IsReflective // no update desired
|| IsInTransfer // in a transfer
)
return;
if (synchronous)
{
UpdateValue();
}
else
{
Engine.AddTask(this, TaskOps.UpdateValue);
}
}
#endregion Value
//------------------------------------------------------
//
// Private Fields
//
//-----------------------------------------------------
Collection _list = new Collection();
IMultiValueConverter _converter;
object[] _tempValues;
Type[] _tempTypes;
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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- ElementHostPropertyMap.cs
- BuilderInfo.cs
- RsaSecurityToken.cs
- WebBrowserProgressChangedEventHandler.cs
- Control.cs
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- SmtpReplyReader.cs
- XmlUtf8RawTextWriter.cs
- DeflateStream.cs
- FastEncoderStatics.cs
- ComponentChangingEvent.cs
- xamlnodes.cs
- CompilerError.cs
- TypeLoadException.cs
- CheckBoxList.cs
- WebConvert.cs
- ParserStack.cs
- CodeTypeMemberCollection.cs
- ErrorWrapper.cs
- FixedSOMTable.cs
- RightsManagementEncryptionTransform.cs
- TextRenderer.cs
- RelationshipDetailsRow.cs
- StringCollection.cs
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- TreeViewItem.cs
- ButtonChrome.cs
- GreenMethods.cs
- UmAlQuraCalendar.cs
- SubpageParaClient.cs
- ToolBarButtonDesigner.cs
- NumericPagerField.cs
- MemberDescriptor.cs
- IgnoreSection.cs
- Path.cs
- DesigntimeLicenseContext.cs
- ZipPackagePart.cs
- DataKey.cs
- DynamicDiscoveryDocument.cs
- HierarchicalDataBoundControlAdapter.cs
- SignerInfo.cs
- SoapAttributeAttribute.cs
- BulletedList.cs
- PeerTransportElement.cs
- SurrogateEncoder.cs
- XomlCompiler.cs
- CacheMemory.cs
- HttpListenerRequest.cs
- Paragraph.cs
- XmlSchemaSubstitutionGroup.cs
- EntityParameterCollection.cs
- RSAPKCS1KeyExchangeDeformatter.cs
- RIPEMD160.cs
- TabControlAutomationPeer.cs
- ResizeGrip.cs
- Blend.cs
- SerializableTypeCodeDomSerializer.cs
- MissingSatelliteAssemblyException.cs
- PixelShader.cs
- SectionInput.cs
- SqlNotificationEventArgs.cs
- SignatureConfirmationElement.cs
- securestring.cs
- Graph.cs
- TypeReference.cs
- WhitespaceRule.cs
- XmlMembersMapping.cs
- ToolbarAUtomationPeer.cs
- RoutedEventValueSerializer.cs
- DragCompletedEventArgs.cs
- TagNameToTypeMapper.cs
- serverconfig.cs
- KeyInstance.cs