Code:
/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Web / UI / WebControls / CompositeDataBoundControl.cs / 1305376 / CompositeDataBoundControl.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.Web.UI.WebControls { using System; using System.Collections; public abstract class CompositeDataBoundControl : DataBoundControl, INamingContainer { internal const string ItemCountViewStateKey = "_!ItemCount"; public override ControlCollection Controls { get { EnsureChildControls(); return base.Controls; } } ////// Overriden by DataBoundControl to determine if the control should /// recreate its control hierarchy based on values in view state. /// If the control hierarchy should be created, i.e. view state does /// exist, it calls CreateChildControls with a dummy (empty) data source /// which is usable for enumeration purposes only. /// protected internal override void CreateChildControls() { Controls.Clear(); object controlCount = ViewState[ItemCountViewStateKey]; if (controlCount == null && RequiresDataBinding) { EnsureDataBound(); } if (controlCount != null && ((int)controlCount) != -1) { DummyDataSource dummyDataSource = new DummyDataSource((int)controlCount); CreateChildControls(dummyDataSource, false); ClearChildViewState(); } } ////// Performs the work of creating the control hierarchy based on a data source. /// When dataBinding is true, the specified data source contains real /// data, and the data is supposed to be pushed into the UI. /// When dataBinding is false, the specified data source is a dummy data /// source, that allows enumerating the right number of items, but the items /// themselves are null and do not contain data. In this case, the recreated /// control hierarchy reinitializes its state from view state. /// It enables a DataBoundControl to encapsulate the logic of creating its /// control hierarchy in both modes into a single code path. /// /// /// The data source to be used to enumerate items. /// /// /// Whether the method has been called from DataBind or not. /// ////// The number of items created based on the data source. Put another way, its /// the number of items enumerated from the data source. /// protected abstract int CreateChildControls(IEnumerable dataSource, bool dataBinding); ////// Overriden by DataBoundControl to use its properties to determine the real /// data source that the control should bind to. It then clears the existing /// control hierarchy, and calls createChildControls to create a new control /// hierarchy based on the resolved data source. /// The implementation resolves various data source related properties to /// arrive at the appropriate IEnumerable implementation to use as the real /// data source. /// When resolving data sources, the DataSourceControlID takes highest precedence. /// In this mode, DataMember is used to access the appropriate list from the /// DataControl. /// If DataSourceControlID is not set, the value of the DataSource property is used. /// In this second alternative, DataMember is used to extract the appropriate /// list if the control has been handed an IListSource as a data source. /// protected internal override void PerformDataBinding(IEnumerable data) { base.PerformDataBinding(data); Controls.Clear(); ClearChildViewState(); TrackViewState(); int controlCount = CreateChildControls(data, true); ChildControlsCreated = true; ViewState[ItemCountViewStateKey] = controlCount; } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. //------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- namespace System.Web.UI.WebControls { using System; using System.Collections; public abstract class CompositeDataBoundControl : DataBoundControl, INamingContainer { internal const string ItemCountViewStateKey = "_!ItemCount"; public override ControlCollection Controls { get { EnsureChildControls(); return base.Controls; } } ////// Overriden by DataBoundControl to determine if the control should /// recreate its control hierarchy based on values in view state. /// If the control hierarchy should be created, i.e. view state does /// exist, it calls CreateChildControls with a dummy (empty) data source /// which is usable for enumeration purposes only. /// protected internal override void CreateChildControls() { Controls.Clear(); object controlCount = ViewState[ItemCountViewStateKey]; if (controlCount == null && RequiresDataBinding) { EnsureDataBound(); } if (controlCount != null && ((int)controlCount) != -1) { DummyDataSource dummyDataSource = new DummyDataSource((int)controlCount); CreateChildControls(dummyDataSource, false); ClearChildViewState(); } } ////// Performs the work of creating the control hierarchy based on a data source. /// When dataBinding is true, the specified data source contains real /// data, and the data is supposed to be pushed into the UI. /// When dataBinding is false, the specified data source is a dummy data /// source, that allows enumerating the right number of items, but the items /// themselves are null and do not contain data. In this case, the recreated /// control hierarchy reinitializes its state from view state. /// It enables a DataBoundControl to encapsulate the logic of creating its /// control hierarchy in both modes into a single code path. /// /// /// The data source to be used to enumerate items. /// /// /// Whether the method has been called from DataBind or not. /// ////// The number of items created based on the data source. Put another way, its /// the number of items enumerated from the data source. /// protected abstract int CreateChildControls(IEnumerable dataSource, bool dataBinding); ////// Overriden by DataBoundControl to use its properties to determine the real /// data source that the control should bind to. It then clears the existing /// control hierarchy, and calls createChildControls to create a new control /// hierarchy based on the resolved data source. /// The implementation resolves various data source related properties to /// arrive at the appropriate IEnumerable implementation to use as the real /// data source. /// When resolving data sources, the DataSourceControlID takes highest precedence. /// In this mode, DataMember is used to access the appropriate list from the /// DataControl. /// If DataSourceControlID is not set, the value of the DataSource property is used. /// In this second alternative, DataMember is used to extract the appropriate /// list if the control has been handed an IListSource as a data source. /// protected internal override void PerformDataBinding(IEnumerable data) { base.PerformDataBinding(data); Controls.Clear(); ClearChildViewState(); TrackViewState(); int controlCount = CreateChildControls(data, true); ChildControlsCreated = true; ViewState[ItemCountViewStateKey] = controlCount; } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- BaseDataList.cs
- ProfileGroupSettingsCollection.cs
- ExpressionParser.cs
- AccessViolationException.cs
- ObjectIDGenerator.cs
- ColorConverter.cs
- Translator.cs
- KerberosSecurityTokenAuthenticator.cs
- metadatamappinghashervisitor.cs
- GcHandle.cs
- MethodBuilderInstantiation.cs
- ParseNumbers.cs
- RightsManagementResourceHelper.cs
- CodeExporter.cs
- PrimitiveCodeDomSerializer.cs
- HostAdapter.cs
- PaginationProgressEventArgs.cs
- MediaCommands.cs
- VBCodeProvider.cs
- ManipulationStartingEventArgs.cs
- WinFormsSecurity.cs
- DataRowCollection.cs
- XmlEncodedRawTextWriter.cs
- BitStack.cs
- PropertyOrder.cs
- Interlocked.cs
- CodeSnippetCompileUnit.cs
- HostedNamedPipeTransportManager.cs
- EventBindingService.cs
- FtpWebRequest.cs
- UIHelper.cs
- FlowPosition.cs
- PropertyCondition.cs
- Pkcs7Signer.cs
- AudioStateChangedEventArgs.cs
- XmlnsDictionary.cs
- InheritanceRules.cs
- HttpPostedFile.cs
- DoubleLinkList.cs
- ObjectDisposedException.cs
- SoundPlayerAction.cs
- TrackingMemoryStreamFactory.cs
- ItemContainerProviderWrapper.cs
- AnnotationMap.cs
- LambdaCompiler.Unary.cs
- ClientSettingsProvider.cs
- PathGradientBrush.cs
- FrameworkReadOnlyPropertyMetadata.cs
- InternalMappingException.cs
- PersonalizationProviderCollection.cs
- HttpSessionStateBase.cs
- Oid.cs
- EdmScalarPropertyAttribute.cs
- Attributes.cs
- mda.cs
- CommandLibraryHelper.cs
- SingleSelectRootGridEntry.cs
- KeyTime.cs
- StrokeNodeOperations2.cs
- RepeaterItemCollection.cs
- securestring.cs
- Pen.cs
- WebRequest.cs
- GetWinFXPath.cs
- KeyboardNavigation.cs
- SpellerHighlightLayer.cs
- HttpProxyTransportBindingElement.cs
- WindowsListViewGroup.cs
- OneOfScalarConst.cs
- Expressions.cs
- MatrixTransform3D.cs
- ExpressionValueEditor.cs
- ScrollChangedEventArgs.cs
- SqlFacetAttribute.cs
- NativeMethods.cs
- ProcessActivityTreeOptions.cs
- BinaryParser.cs
- RSAPKCS1KeyExchangeDeformatter.cs
- AttachInfo.cs
- CapabilitiesUse.cs
- DbInsertCommandTree.cs
- QueryableDataSourceEditData.cs
- InfiniteTimeSpanConverter.cs
- DbDataRecord.cs
- C14NUtil.cs
- _AuthenticationState.cs
- UserCancellationException.cs
- Button.cs
- FilteredAttributeCollection.cs
- PaperSource.cs
- CodeDirectionExpression.cs
- BitmapEffectInput.cs
- RegexMatchCollection.cs
- RectConverter.cs
- COSERVERINFO.cs
- AuditLogLocation.cs
- UiaCoreApi.cs
- RawContentTypeMapper.cs
- WebConfigurationHostFileChange.cs
- ImageMapEventArgs.cs