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//---------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
// File: CultureInfoConverter.cs
//
// Description: Contains the CultureInfoIetfLanguageTagConverter: TypeConverter for the CultureInfo class.
//
// History:
// 01/12/2005 : niklasb - Initial implementation
// 02/10/2006 : niklasb - Renamed from CulutureInfoConveter to CultureInfoIetfLanguageTagConverter
//
//---------------------------------------------------------------------------
using System;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Diagnostics;
using System.Globalization;
using System.Reflection;
using System.Security;
namespace System.Windows
{
/// <summary>
/// CultureInfoIetfLanguageTagConverter - Type converter for converting instances of other types to and from CultureInfo.
/// </summary>
/// <remarks>
/// This class differs in two ways from System.ComponentModel.CultureInfoConverter, the default type converter
/// for the CultureInfo class. First, it uses a string representation based on the IetfLanguageTag property
/// rather than the Name property (i.e., RFC 3066 rather than RFC 1766). Second, when converting from a string,
/// the properties of the resulting CultureInfo object depend only on the string and not on user overrides set
/// in Control Panel. This makes it possible to create documents the appearance of which do not depend on
/// local settings.
/// </remarks>
public class CultureInfoIetfLanguageTagConverter : TypeConverter
{
//-------------------------------------------------------------------
//
// Public Methods
//
//-------------------------------------------------------------------
#region Public Methods
/// <summary>
/// CanConvertFrom - Returns whether or not this class can convert from a given type.
/// </summary>
/// <returns>
/// bool - True if this converter can convert from the provided type, false if not.
/// </returns>
/// <param name="typeDescriptorContext"> The ITypeDescriptorContext for this call. </param>
/// <param name="sourceType"> The Type being queried for support. </param>
public override bool CanConvertFrom(ITypeDescriptorContext typeDescriptorContext, Type sourceType)
{
// We can only handle strings.
return sourceType == typeof(string);
}
/// <summary>
/// CanConvertTo - Returns whether or not this class can convert to a given type.
/// </summary>
/// <returns>
/// bool - True if this converter can convert to the provided type, false if not.
/// </returns>
/// <param name="typeDescriptorContext"> The ITypeDescriptorContext for this call. </param>
/// <param name="destinationType"> The Type being queried for support. </param>
public override bool CanConvertTo(ITypeDescriptorContext typeDescriptorContext, Type destinationType)
{
// We can convert to an InstanceDescriptor or to a string.
return destinationType == typeof(InstanceDescriptor) ||
destinationType == typeof(string);
}
/// <summary>
/// ConvertFrom - Attempt to convert to a CultureInfo from the given object
/// </summary>
/// <returns>
/// A CultureInfo object based on the specified culture name.
/// </returns>
/// <exception cref="ArgumentNullException">
/// An ArgumentNullException is thrown if the example object is null.
/// </exception>
/// <exception cref="ArgumentException">
/// An ArgumentException is thrown if the example object is not null and is not a valid type
/// which can be converted to a CultureInfo.
/// </exception>
/// <param name="typeDescriptorContext">The ITypeDescriptorContext for this call.</param>
/// <param name="cultureInfo">The CultureInfo which is respected when converting.</param>
/// <param name="source">The object to convert to a CultureInfo.</param>
public override object ConvertFrom(ITypeDescriptorContext typeDescriptorContext,
CultureInfo cultureInfo,
object source)
{
string cultureName = source as string;
if (cultureName != null)
{
return CultureInfo.GetCultureInfoByIetfLanguageTag(cultureName);
}
throw GetConvertFromException(source);
}
/// <summary>
/// ConvertTo - Attempt to convert a CultureInfo to the given type
/// </summary>
/// <returns>
/// The object which was constructed.
/// </returns>
/// <exception cref="ArgumentNullException">
/// An ArgumentNullException is thrown if the example object is null.
/// </exception>
/// <exception cref="ArgumentException">
/// An ArgumentException is thrown if the example object is not null and is not a CultureInfo,
/// or if the destinationType isn't one of the valid destination types.
/// </exception>
/// <param name="typeDescriptorContext"> The ITypeDescriptorContext for this call. </param>
/// <param name="cultureInfo"> The CultureInfo which is respected when converting. </param>
/// <param name="value"> The double to convert. </param>
/// <param name="destinationType">The type to which to convert the CultureInfo. </param>
///<SecurityNote>
/// Critical: calls InstanceDescriptor ctor which LinkDemands
/// PublicOK: can only make an InstanceDescriptor for CultureInfo.GetCultureInfo, not an arbitrary class/method
///</SecurityNote>
[SecurityCritical]
public override object ConvertTo(ITypeDescriptorContext typeDescriptorContext,
CultureInfo cultureInfo,
object value,
Type destinationType)
{
if (destinationType == null)
{
throw new ArgumentNullException("destinationType");
}
CultureInfo culture = value as CultureInfo;
if (culture != null)
{
if (destinationType == typeof(string))
{
return culture.IetfLanguageTag;
}
else if (destinationType == typeof(InstanceDescriptor))
{
MethodInfo method = typeof(CultureInfo).GetMethod(
"GetCultureInfo",
BindingFlags.Static | BindingFlags.InvokeMethod | BindingFlags.Public,
null, // use default binder
new Type[] { typeof(string) },
null // default binder doesn't use parameter modifiers
);
return new InstanceDescriptor(method, new object[] { culture.Name });
}
}
throw GetConvertToException(value, destinationType);
}
#endregion
}
}
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