ListBindingConverter.cs source code in C# .NET

                        Code:
                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / WinForms / Managed / System / WinForms / ListBindingConverter.cs / 1 / ListBindingConverter.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Windows.Forms { 
 
    using System;
    using System.Diagnostics; 
    using System.ComponentModel;
    using System.ComponentModel.Design.Serialization;
    using System.Collections;
    using System.Globalization; 
    using System.Reflection;
 
    ///  
    /// 
    ///    [To be supplied.] 
    /// 
    public class ListBindingConverter : TypeConverter {

        private static Type[] ctorTypes = null;  // the list of type of our ctor parameters. 
        private static string[] ctorParamProps = null; // the name of each property to check to see if we need to init with a ctor.
 
        ///  
        ///      Creates our array of types on demand.
        ///  
        private static Type[] ConstructorParamaterTypes {
            get {
                if (ctorTypes == null) {
                    ctorTypes = new Type[]{typeof(string), typeof(object), typeof(string), typeof(bool), typeof(DataSourceUpdateMode), typeof(object), typeof(string), typeof(IFormatProvider)}; 
                }
                return ctorTypes; 
            } 
        }
 
        /// 
        ///      Creates our array of param names on demand.
        /// 
 
        private static string[] ConstructorParameterProperties {
            get { 
                if (ctorParamProps == null) { 
                    ctorParamProps = new string[]{null, null, null, "FormattingEnabled", "DataSourceUpdateMode", "NullValue", "FormatString", "FormatInfo", };
                } 
                return ctorParamProps;
            }
        }
 

        ///  
        ///  
        ///    Gets a value indicating whether this converter can
        ///       convert an object to the given destination type using the context. 
        /// 
        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
            if (destinationType == typeof(InstanceDescriptor)) {
                return true; 
            }
            return base.CanConvertTo(context, destinationType); 
        } 

        ///  
        /// 
        ///      Converts the given object to another type.  The most common types to convert
        ///      are to and from a string object.  The default implementation will make a call
        ///      to ToString on the object if the object is valid and if the destination 
        ///      type is string.  If this cannot convert to the desitnation type, this will
        ///      throw a NotSupportedException. 
        ///  
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
            if (destinationType == null) { 
                throw new ArgumentNullException("destinationType");
            }

            if (destinationType == typeof(InstanceDescriptor) && value is Binding) { 
                Binding b = (Binding)value;
                return GetInstanceDescriptorFromValues(b); 
            } 

            return base.ConvertTo(context, culture, value, destinationType); 
        }

        /// 
        ///  
        ///      Creates an instance of this type given a set of property values
        ///      for the object.  This is useful for objects that are immutable, but still 
        ///      want to provide changable properties. 
        /// 
        public override object CreateInstance(ITypeDescriptorContext context, IDictionary propertyValues) { 
            try
            {
                return new Binding((string)propertyValues["PropertyName"],
                                           propertyValues["DataSource"], 
                                   (string)propertyValues["DataMember"]);
            } 
            catch (InvalidCastException invalidCast) 
            {
                throw new ArgumentException(SR.GetString(SR.PropertyValueInvalidEntry), invalidCast); 
            }
            catch (NullReferenceException nullRef)
            {
                throw new ArgumentException(SR.GetString(SR.PropertyValueInvalidEntry), nullRef); 
            }
        } 
 
        /// 
        ///  
        ///      Determines if changing a value on this object should require a call to
        ///      CreateInstance to create a new value.
        /// 
        public override bool GetCreateInstanceSupported(ITypeDescriptorContext context) { 
            return true;
        } 
 
        /// 
        ///      Gets the best matching ctor for a given binding and fills it out, based on the 
        ///      state of the Binding and the optimal ctor.
        /// 
        private InstanceDescriptor GetInstanceDescriptorFromValues(Binding b) {
 
            // The BindingFormattingDialog turns on Binding::FormattingEnabled property.
            // however, when the user data binds a property using the PropertyBrowser, Binding::FormattingEnabled is set to false 
            // The Binding class is not a component class, so we don't have the ComponentInitialize method where we can set FormattingEnabled to true 
            // so we set it here. VsWhidbey 241361
            b.FormattingEnabled = true; 

            bool isComplete = true;
            int lastItem = ConstructorParameterProperties.Length - 1;
 
            for (; lastItem >= 0; lastItem--) {
 
                // null means no prop is available, we quit here. 
                //
                if (ConstructorParameterProperties[lastItem] == null) { 
                    break;
                }

                // get the property and see if it needs to be serialized. 
                //
                PropertyDescriptor prop = TypeDescriptor.GetProperties(b)[ConstructorParameterProperties[lastItem]]; 
                if (prop != null && prop.ShouldSerializeValue(b)) { 
                    break;
                } 
            }

            // now copy the type array up to the point we quit.
            // 
            Type[] ctorParams = new Type[lastItem + 1];
            Array.Copy(ConstructorParamaterTypes, 0, ctorParams, 0, ctorParams.Length); 
 
            // Get the ctor info.
            // 
            ConstructorInfo ctor = typeof(Binding).GetConstructor(ctorParams);
            Debug.Assert(ctor != null, "Failed to find Binding ctor for types!");
            if (ctor == null) {
                isComplete = false; 
                ctor = typeof(Binding).GetConstructor(new Type[] {
                   typeof(string), 
                   typeof(object), 
                   typeof(string)});
            } 

            // now fill in the values.
            //
            object[] values = new object[ctorParams.Length]; 

            for (int i = 0; i < values.Length; i++) { 
                object val = null; 
                switch (i) {
                    case 0: 
                        val = b.PropertyName;
                        break;
                    case 1:
                        val = b.BindToObject.DataSource; 
                        break;
                    case 2: 
                        val = b.BindToObject.BindingMemberInfo.BindingMember; 
                        break;
                    default: 
                        val = TypeDescriptor.GetProperties(b)[ConstructorParameterProperties[i]].GetValue(b);
                        break;
                }
                values[i] = val; 
            }
            return new InstanceDescriptor(ctor, values, isComplete); 
        } 
    }
} 


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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ListBindingConverter.cs source code in C# .NET

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