/// <summary>
/// Destroys the render context provider instance.
/// </summary>
protected override void DisposeUnmanagedResources()
{
// Release the device context.
Win32.ReleaseDC(windowHandle, this.DeviceContextHandle);
// Destroy the window.
Win32.DestroyWindow(windowHandle);
// Call the base, which will delete the render context handle.
base.DisposeUnmanagedResources();
}