Reflect Attribute : Attributes « Reflection « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Reflection
3. Attributes

using System;
using System.Reflection;


    [AttributeUsage( AttributeTargets.Parameter )]
    public class ArgumentUsageAttribute : Attribute
    {
        public ArgumentUsageAttribute( string UsageMsg )
        {
            this.usageMsg = UsageMsg;
        }
        protected string usageMsg;
        public override string ToString( )
        {
            return base.ToString( ) + ":" + usageMsg;
        }
    }

    [AttributeUsage( AttributeTargets.Parameter )]
    public class ArgumentIDAttribute : Attribute
    {
        public ArgumentIDAttribute( )
        {
            this.instanceGUID = Guid.NewGuid( );
        }
        protected Guid instanceGUID;
        public override string ToString( )
        {
            return base.ToString( ) + "." + instanceGUID.ToString( );
        }
    }

    public class TestClass 
    {
        public void TestMethod(
            [ArgumentID]
            [ArgumentUsage("message.")]
            String[] strArray,
            [ArgumentID]
            [ArgumentUsage("a test.")]
            params String[] strList)
        { }
    }

    class AttributeEqualsDemo 
    {
        static void Main( ) 
        {
            Type clsType = typeof( TestClass );
            MethodInfo mInfo = clsType.GetMethod("TestMethod");

            ParameterInfo[] pInfoArray = mInfo.GetParameters();
            if (pInfoArray != null) 
            {
                ArgumentUsageAttribute arrayUsageAttr1 = (ArgumentUsageAttribute)
                    Attribute.GetCustomAttribute( pInfoArray[0], 
                        typeof(ArgumentUsageAttribute) );

                ArgumentUsageAttribute arrayUsageAttr2 = (ArgumentUsageAttribute)
                    Attribute.GetCustomAttribute( pInfoArray[0], 
                        typeof(ArgumentUsageAttribute) );

                Console.WriteLine( "   \"{0}\" == \n   \"{1}\" ? {2}",
                    arrayUsageAttr1.ToString(), arrayUsageAttr2.ToString(), 
                    arrayUsageAttr1.Equals( arrayUsageAttr2 ) );

            }
        }
    }