ListViewGroupConverter.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / WinForms / Managed / System / WinForms / ListViewGroupConverter.cs / 1 / ListViewGroupConverter.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/* 
 */ 
namespace System.Windows.Forms {
    using System.Runtime.Serialization.Formatters; 
    using System.Runtime.Remoting;
    using System.Runtime.InteropServices;

    using Microsoft.Win32; 
    using System.Collections;
    using System.ComponentModel; 
    using System.ComponentModel.Design.Serialization; 
    using System.Drawing;
    using System.Diagnostics; 
    using System.Globalization;
    using System.Reflection;

    ///  
    /// 
    ///      ListViewGroupConverter is a class that can be used to convert 
    ///      ListViewGroup objects from one data type to another.  Access this 
    ///      class through the TypeDescriptor.
    ///  
    internal class ListViewGroupConverter : TypeConverter {

        /// 
        ///  
        ///      Determines if this converter can convert an object in the given source
        ///      type to the native type of the converter. 
        ///  
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
            if (sourceType == typeof(string) && context != null && context.Instance is ListViewItem) { 
                return true;
            }
            return base.CanConvertFrom(context, sourceType);
        } 

        ///  
        ///  
        ///    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; 
            }
            if (destinationType == typeof(string) && context != null && context.Instance is ListViewItem) { 
                return true; 
            }
            return base.CanConvertTo(context, destinationType); 
        }

        /// 
        ///  
        ///      Converts the given object to the converter's native type.
        ///  
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) { 

            if (value is string) { 
                string text = ((string)value).Trim();

                if (context != null && context.Instance != null) {
                    ListViewItem item = context.Instance as ListViewItem; 
                    if (item != null && item.ListView != null) {
 
                        foreach(ListViewGroup group in item.ListView.Groups) { 
                            if (group.Header == text) {
                                return group; 
                            }
                        }
                    }
                } 
            }
 
            if (value == null || value.Equals(SR.GetString(SR.toStringNone))) { 
                return null;
            } 

            return base.ConvertFrom(context, culture, value);
        }
 
        /// 
        ///  
        ///      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 ListViewGroup) { 
                ListViewGroup group = (ListViewGroup)value;
                ConstructorInfo ctor;

                // Header 
                //
                ctor = typeof(ListViewGroup).GetConstructor(new Type[] {typeof(string), typeof(HorizontalAlignment)}); 
                if (ctor != null) { 
                    return new InstanceDescriptor(ctor, new object[] { group.Header, group.HeaderAlignment }, false);
                } 
            }

            if (destinationType == typeof(string) && value == null) {
                return SR.GetString(SR.toStringNone); 
            }
 
            return base.ConvertTo(context, culture, value, destinationType); 
        }
 
        /// 
        /// 
        ///      Retrieves a collection containing a set of standard values
        ///      for the data type this validator is designed for.  This 
        ///      will return null if the data type does not support a
        ///      standard set of values. 
        ///  
        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) {
            if (context != null && context.Instance != null) { 
                ListViewItem item = context.Instance as ListViewItem;
                if (item != null && item.ListView != null) {
                    ArrayList list = new ArrayList();
                    foreach (ListViewGroup group in item.ListView.Groups) { 
                        list.Add(group);
                    } 
                    list.Add(null); 
                    return new StandardValuesCollection(list);
                } 
            }
            return null;
        }
 
        /// 
        ///  
        ///      Determines if the list of standard values returned from 
        ///      GetStandardValues is an exclusive list.  If the list
        ///      is exclusive, then no other values are valid, such as 
        ///      in an enum data type.  If the list is not exclusive,
        ///      then there are other valid values besides the list of
        ///      standard values GetStandardValues provides.
        ///  
        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context) {
            return true; 
        } 

        ///  
        /// 
        ///      Determines if this object supports a standard set of values
        ///      that can be picked from a list.
        ///  
        public override bool GetStandardValuesSupported(ITypeDescriptorContext context) {
            return true; 
        } 
    }
} 


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.


                        

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