StaticExtension.cs source code in C# .NET

                        Code:
                         / DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Framework / System / Windows / Markup / StaticExtension.cs / 1 / StaticExtension.cs
                        
                        
                            /****************************************************************************\ 
*
* File: StaticExtension.cs
*
*  Class for Xaml markup extension for static field and property references. 
*
* Copyright (C) 2004 by Microsoft Corporation.  All rights reserved. 
* 
\***************************************************************************/
 
using System;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Windows; 
using System.Windows.Input;
using System.Reflection; 
using MS.Utility; 

namespace System.Windows.Markup 
{
    /// 
    ///  Class for Xaml markup extension for static field and property references.
    ///  
    [TypeConverter(typeof(StaticExtensionConverter))]
    [MarkupExtensionReturnType(typeof(object))] 
    public class StaticExtension : MarkupExtension 
    {
        ///  
        ///  Constructor that takes no parameters
        /// 
        public StaticExtension()
        { 
        }
 
        ///  
        ///  Constructor that takes the member that this is a static reference to.
        ///  This string is of the format 
        ///     Prefix:ClassName.FieldOrPropertyName.  The Prefix is
        ///  optional, and refers to the XML prefix in a Xaml file.
        /// 
        public StaticExtension( 
            string   member)
        { 
            if (member == null) 
            {
                throw new ArgumentNullException("member"); 
            }
            _member = member;
        }
 
        /// 
        ///  Return an object that should be set on the targetObject's targetProperty 
        ///  for this markup extension.  For a StaticExtension this is a static field 
        ///  or property value.
        ///  
        /// Object that can provide services for the markup extension.
        /// 
        ///  The object to set on this property.
        ///  
        public override object ProvideValue(IServiceProvider serviceProvider)
        { 
            if (_member == null) 
            {
                throw new InvalidOperationException(SR.Get(SRID.MarkupExtensionStaticMember)); 
            }

            object value = null;
            Type type = MemberType; 
            string fieldString = null;
            string memberFullName = null; 
            if (type != null) 
            {
                fieldString = _member; 
                memberFullName = type.FullName + "." + _member;
            }
            else
            { 
                memberFullName = _member;
 
                // optimize for some well known common resource keys defined by known controls. 
                // if found just return the value, else use reflection to get the value.
                // This optimization can be removed from here in the future, if the Baml record 
                // for resource keys is optimized to store this info.
                value = SystemResourceKey.GetSystemResourceKey(_member);
                if (value != null)
                { 
                    return value;
                } 
 
                // Validate the _member
 
                int dotIndex = _member.IndexOf('.');
                if (dotIndex < 0)
                {
                    throw new ArgumentException(SR.Get(SRID.MarkupExtensionBadStatic, _member)); 
                }
 
                // Pull out the type substring (this will include any XML prefix, e.g. "av:Button") 

                string typeString = _member.Substring(0, dotIndex); 
                if (typeString == string.Empty)
                {
                    throw new ArgumentException(SR.Get(SRID.MarkupExtensionBadStatic, _member));
                } 

                // Get the IXamlTypeResolver from the service provider 
 
                IXamlTypeResolver xamlTypeResolver = serviceProvider.GetService(typeof(IXamlTypeResolver)) as IXamlTypeResolver;
                if (xamlTypeResolver == null) 
                {
                    throw new ArgumentException(SR.Get(SRID.MarkupExtensionNoContext, GetType().Name, "IXamlTypeResolver"));
                }
 
                // Use the type resolver to get a Type instance
 
                type = xamlTypeResolver.Resolve(typeString); 

                // Get the member name substring 

                fieldString = _member.Substring(dotIndex + 1, _member.Length - dotIndex - 1);
                if (fieldString == string.Empty)
                { 
                    throw new ArgumentException(SR.Get(SRID.MarkupExtensionBadStatic, _member));
                } 
            } 

            // optimize for some well known common commands defined by known controls. 
            // if found just return the value, else use reflection to get the value.
            // This optimization can be removed from here in the future, if each known
            // or registered command is mapped to a CommandId that is then stored in the
            // Baml record insated of the string for the command name. 
            value = CommandConverter.GetKnownControlCommand(type, fieldString);
            if (value != null) 
            { 
                return value;
            } 

            // Use the built-in parser for enum types

            if (type.IsEnum) 
            {
                return Enum.Parse(type, fieldString); 
            } 

            // For other types, reflect 

            bool found = false;

            object fieldOrProp = type.GetField(fieldString, BindingFlags.Public | 
                             BindingFlags.FlattenHierarchy | BindingFlags.Static);
            if (fieldOrProp == null) 
            { 
                fieldOrProp = type.GetProperty(fieldString, BindingFlags.Public |
                              BindingFlags.FlattenHierarchy | BindingFlags.Static); 
                if (fieldOrProp is PropertyInfo)
                {
                    value = ((PropertyInfo)fieldOrProp).GetValue(null,null);
                    found = true; 
                }
            } 
            else if (fieldOrProp is FieldInfo) 
            {
                value = ((FieldInfo)fieldOrProp).GetValue(null); 
                found = true;
            }

            if (found) 
            {
                return value; 
            } 
            else
            { 
                throw new ArgumentException(SR.Get(SRID.MarkupExtensionBadStatic, memberFullName));
            }
        }
 
        /// 
        ///  The static field or property represented by a string.  This string is 
        ///  of the format Prefix:ClassName.FieldOrPropertyName.  The Prefix is 
        ///  optional, and refers to the XML prefix in a Xaml file.
        ///  
        [ConstructorArgument("member")]
        public string Member
        {
            get { return _member; } 
            set
            { 
                if (value == null) 
                {
                    throw new ArgumentNullException("value"); 
                }
                _member = value;
            }
        } 

        internal Type MemberType 
        { 
            get { return _memberType; }
            set 
            {
                if (value == null)
                {
                    throw new ArgumentNullException("value"); 
                }
                _memberType = value; 
            } 
        }
 
        private string _member;
        private Type _memberType;
    }
} 


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

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