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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.Diagnostics.CodeAnalysis;
using System.Globalization;
namespace System.ComponentModel
{
/// <summary>
/// Provides a type converter to convert <see cref='System.Array'/>
/// objects to and from various other representations.
/// </summary>
public class ArrayConverter : CollectionConverter
{
/// <summary>
/// Converts the given value object to the specified destination type.
/// </summary>
public override object? ConvertTo(ITypeDescriptorContext? context, CultureInfo? culture, object? value, Type destinationType)
{
if (destinationType == typeof(string) && value is Array)
{
return SR.Format(SR.UsingResourceKeys() ? "{0} Array" : SR.Array, value.GetType().Name);
}
return base.ConvertTo(context, culture, value, destinationType);
}
/// <summary>
/// Gets a collection of properties for the type of array specified by the value parameter.
/// </summary>
[RequiresUnreferencedCode("The Type of value cannot be statically discovered. " + AttributeCollection.FilterRequiresUnreferencedCodeMessage)]
[return: NotNullIfNotNull(nameof(value))]
public override PropertyDescriptorCollection? GetProperties(ITypeDescriptorContext? context, object? value, Attribute[]? attributes)
{
if (value == null)
{
return null;
}
if (!(value is Array valueArray))
{
return new PropertyDescriptorCollection(null);
}
int length = valueArray.GetLength(0);
PropertyDescriptor[] props = new PropertyDescriptor[length];
Type arrayType = value.GetType();
Type elementType = arrayType.GetElementType()!;
for (int i = 0; i < length; i++)
{
props[i] = new ArrayPropertyDescriptor(arrayType, elementType, i);
}
return new PropertyDescriptorCollection(props);
}
/// <summary>
/// Gets a value indicating whether this object supports properties.
/// </summary>
public override bool GetPropertiesSupported(ITypeDescriptorContext? context) => true;
private sealed class ArrayPropertyDescriptor : SimplePropertyDescriptor
{
private readonly int _index;
public ArrayPropertyDescriptor(Type arrayType, Type elementType, int index)
: base(arrayType, "[" + index + "]", elementType, null)
{
_index = index;
}
public override object? GetValue(object? instance)
{
if (instance is Array array && array.GetLength(0) > _index)
{
return array.GetValue(_index);
}
return null;
}
public override void SetValue(object? instance, object? value)
{
if (instance is Array array)
{
if (array.GetLength(0) > _index)
{
array.SetValue(value, _index);
}
OnValueChanged(instance, EventArgs.Empty);
}
}
}
}
}
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