Use .NET Reflection APIs to facilitate get/set property

//---------------------------------------------------------------------
//
// Copyright (C) 2005 Hongju Cao <hjcao_wei@hotmail.com>
//
// Permission to copy, use, modify, sell and distribute this software is 
// granted provided this copyright notice appears in all copies. 
// This software is provided "as is" without express or implied warranty, 
// and with no claim as to its suitability for any purpose.
//
//---------------------------------------------------------------------

using System;
using System.Collections;

namespace First.Commons.Property
{
	/// <summary>
	/// DictionaryProxy ��ժҪ˵����
	/// </summary>
	internal sealed class DictionaryProxy : IDynaAccessProxy
	{
		private string[] _propertyNames = new string[0];

		public DictionaryProxy()
		{
			//
			// TODO: �ڴ˴���ӹ��캯���߼�
			//
		}

		#region IDynaAccessProxy methods

		public string[] GetPropertyNames(object target)
		{
			if (target is IDictionary) 
			{
				string [] propertyNames =  new string[((IDictionary) target).Count];
				((IDictionary) target).Keys.CopyTo(propertyNames,0);
				return propertyNames;
			} 
			else 
			{
				return _propertyNames;
			}
		}

		public void	SetProperty(object target , string propertyName , object propertyValue)
		{
			try 
			{
				if (target is IDictionary) 
				{
					((IDictionary) target)[propertyName] = propertyValue;
				} 
				else 
				{
					throw new DynaAccessException(target.GetType().Name + " class is not a IDictionary.");
				}
			}
			catch(Exception e)
			{
				throw new DynaAccessException(e);
			}
		}

		public object	GetProperty(object target , string propertyName)
		{
			object value = null;

			try 
			{
				if (target is IDictionary) 
				{
					value = ((IDictionary) target)[propertyName];
				} 
				else 
				{
					throw new DynaAccessException(target.GetType().Name + " class is not IDictionary.");
				}
			}
			catch(Exception e)
			{
				throw new DynaAccessException(e);
			}
			return value;
		}

		public bool HasProperty(object target , string propertyName)
		{
			if (target is IDictionary) 
			{
				try
				{
					return ((IDictionary) target).Contains(propertyName);
				}
				catch(Exception)
				{
					return false;
				}
			} 
			else 
			{
				return false;
			}
		}

		public Type GetPropertyType(object target , string propertyName)
		{
			object value = null;

			try 
			{
				if (target is IDictionary) 
				{
					value = ((IDictionary) target)[propertyName];
					if(value == null)
					{
						value  = new object();
					}

					return value.GetType();
				} 
				else 
				{
					throw new DynaAccessException(target.GetType().Name + " class is not a IDictionary.");
				}
			}
			catch(Exception e)
			{
				throw new DynaAccessException(e);
			}
		}

		public Type ProxyType
		{
			get
			{
				return typeof(System.Collections.IDictionary);
			}
		}

		#endregion
	}
}