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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Globalization;
using System.Reflection;
namespace System.Windows.Forms;
public class ColumnHeaderConverter : ExpandableObjectConverter
{
/// <summary>
/// Gets a value indicating whether this converter can
/// convert an object to the given destination type using the context.
/// </summary>
public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
{
if (destinationType == typeof(InstanceDescriptor))
{
return true;
}
return base.CanConvertTo(context, destinationType);
}
/// <summary>
/// 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 destination type, this will
/// throw a NotSupportedException.
/// </summary>
public override object? ConvertTo(ITypeDescriptorContext? context, CultureInfo? culture, object? value, Type destinationType)
{
ArgumentNullException.ThrowIfNull(destinationType);
if (destinationType == typeof(InstanceDescriptor) && value is ColumnHeader col)
{
ConstructorInfo? ctor;
Type t = TypeDescriptor.GetReflectionType(value);
InstanceDescriptor? id = null;
if (col.ImageIndex != -1)
{
ctor = t.GetConstructor([typeof(int)]);
if (ctor is not null)
{
id = new InstanceDescriptor(ctor, new object[] { col.ImageIndex }, false);
}
}
if (id is null && !string.IsNullOrEmpty(col.ImageKey))
{
ctor = t.GetConstructor([typeof(string)]);
if (ctor is not null)
{
id = new InstanceDescriptor(ctor, new object[] { col.ImageKey }, false);
}
}
if (id is null)
{
ctor = t.GetConstructor([]);
if (ctor is not null)
{
return new InstanceDescriptor(ctor, Array.Empty<object>(), false);
}
else
{
throw new ArgumentException(string.Format(SR.NoDefaultConstructor, t.FullName));
}
}
return id;
}
return base.ConvertTo(context, culture, value, destinationType);
}
}
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