Simplified Resource Management with the DisposableCollection Class

////////////////////////////////////////////////////////////////////////////////////
// DisposableCollection.cs
//
// By Scott McMaster (smcmaste@hotmail.com)
// 09/24/2004
//
// THIS CODE AND INFORMATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, 
// EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES 
// OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
////////////////////////////////////////////////////////////////////////////////////
using System;
using System.Collections;

namespace ScottMcMaster
{
	/// <summary>
	/// Implement a collection of Disposable objects that is itself
	/// disposable, the goal being to provide a convenient programming model
	/// for working with multiple disposable objects at the same time.
	/// </summary>
	public sealed class DisposableCollection : CollectionBase, IDisposable
	{
		private bool disposed;

		public DisposableCollection()
		{
			disposed = false;
		}

		~DisposableCollection()
		{
			Dispose(false);
		}

		private void ThrowIfDisposed()
		{
			if( disposed )
			{
				throw new ObjectDisposedException( this.GetType().Name );
			}
		}

		private void Dispose(bool disposing)
		{
			lock(this)
			{
				// Check to see if Dispose has already been called.
				if(!this.disposed)
				{
					if( disposing )
					{
						// Dispose managed resources
						foreach( IDisposable target in List )
						{
							// Watch out for somebody adding the DisposableCollection to itself
							// lest we overflow the stack.
							if( target != this )
							{
								target.Dispose();
							}
						}
						List.Clear();
					}
				}
				disposed = true;
			}
		}

		#region CollectionBase Implementation

		public IDisposable this[ int index ]  
		{
			get  
			{
				ThrowIfDisposed();
				return( (IDisposable) List[index] );
			}
			set  
			{
				ThrowIfDisposed();
				List[index] = value;
			}
		}

		public int Add( IDisposable value )  
		{
			ThrowIfDisposed();
			return( List.Add( value ) );
		}

		public int IndexOf( IDisposable value )  
		{
			ThrowIfDisposed();
			return( List.IndexOf( value ) );
		}

		public void Insert( int index, IDisposable value )  
		{
			ThrowIfDisposed();
			List.Insert( index, value );
		}

		public void Remove( IDisposable value )  
		{
			ThrowIfDisposed();
			List.Remove( value );
		}

		public bool Contains( IDisposable value )  
		{
			ThrowIfDisposed();
			return( List.Contains( value ) );
		}

		#endregion

		#region IDisposable Members

		public void Dispose()
		{
			Dispose(true);
			// Take yourself off the Finalization queue 
			// to prevent finalization code for this object
			// from executing a second time.
			GC.SuppressFinalize(this);
		}

		#endregion
	}
}