public override object CreateNativeBackend ()
{
imageBuilder = toolkit.ImageBuilderBackendHandler.CreateImageBuilder ((int)width, (int)height, ImageFormat.ARGB32);
if (toolkit.ImageBuilderBackendHandler.DisposeHandleOnUiThread)
ResourceManager.RegisterResource (imageBuilder);
else
GC.SuppressFinalize (this);
return toolkit.ImageBuilderBackendHandler.CreateContext (imageBuilder);
}