Garbage collector for unmanaged resources.

The garbage collector only cleans up managed resources.

If your class uses unmanaged resources, then you should implement the IDisposable interface. You can then call the Dispose() method to clean up the unmanaged resources immediately.

There is in fact a pattern which you can use for this purpose. Check out:

http://msdn.microsoft.com/en-us/library/system.idisposable.aspx