Releases the unmanaged resources used by the used by the System.Windows.Forms.ImageList, and optionally releases managed resources.
Call ImageList.Dispose(bool) when you are finished using the System.Windows.Forms.ImageList. The ImageList.Dispose(bool) method leaves the System.Windows.Forms.ImageList in an unusable state.
Always call ImageList.Dispose(bool) before you release your last reference to the System.Windows.Forms.ImageList. Otherwise, the resources the System.Windows.Forms.ImageList is using will not be freed until garbage collection calls the System.Windows.Forms.ImageList object's destructor.