public void Update()
{
if (_thumbHandle == IntPtr.Zero)
{
return;
}
DWMApi.DwmQueryThumbnailSourceSize(_thumbHandle, out PSIZE size);
var props = new DWM_THUMBNAIL_PROPERTIES
{
fVisible = true,
dwFlags = DWMApi.DWM_TNP_VISIBLE | DWMApi.DWM_TNP_RECTDESTINATION | DWMApi.DWM_TNP_OPACITY,
opacity = 255,
rcDestination = _targetRect
};
if (size.x < _targetRect.Width)
{
props.rcDestination.Right = props.rcDestination.Left + size.x;
}
if (size.y < _targetRect.Height)
{
props.rcDestination.Bottom = props.rcDestination.Top + size.y;
}
DWMApi.DwmUpdateThumbnailProperties(_thumbHandle, ref props);
}
public static extern int DwmUpdateThumbnailProperties(IntPtr hThumb, ref DWM_THUMBNAIL_PROPERTIES props);
