private void InitialiseThumbnail(IntPtr source)
{
if (IntPtr.Zero != thumb)
{
// release the old thumbnail
ReleaseThumbnail();
}
if (IntPtr.Zero != source)
{
// find our parent hwnd
target = (HwndSource)HwndSource.FromVisual(this);
// if we have one, we can attempt to register the thumbnail
if (target != null && 0 == Interop.DwmRegisterThumbnail(target.Handle, source, out this.thumb))
{
Interop.ThumbnailProperties props = new Interop.ThumbnailProperties();
props.Visible = false;
props.SourceClientAreaOnly = this.ClientAreaOnly;
props.Opacity = (byte)(255 * this.Opacity);
props.Flags = Interop.ThumbnailFlags.Visible | Interop.ThumbnailFlags.SourceClientAreaOnly
| Interop.ThumbnailFlags.Opacity;
Interop.DwmUpdateThumbnailProperties(thumb, ref props);
}
}
}
private void UpdateThumbnail()
{
if (IntPtr.Zero != thumb)
{
Interop.ThumbnailProperties props = new Interop.ThumbnailProperties();
props.SourceClientAreaOnly = this.ClientAreaOnly;
props.Opacity = (byte)(255 * this.Opacity);
props.Flags = Interop.ThumbnailFlags.SourceClientAreaOnly | Interop.ThumbnailFlags.Opacity;
Interop.DwmUpdateThumbnailProperties(thumb, ref props);
}
}
// this is where the magic happens
private void Thumbnail_LayoutUpdated(object sender, EventArgs e)
{
if (IntPtr.Zero == thumb)
{
InitialiseThumbnail(this.Source);
}
if (IntPtr.Zero != thumb)
{
if (target.RootVisual == null || !target.RootVisual.IsAncestorOf(this))
{
//we are no longer in the visual tree
ReleaseThumbnail();
return;
}
GeneralTransform transform = TransformToAncestor(target.RootVisual);
Point a = transform.Transform(new Point(0, 0));
if (double.IsNaN(a.X))
{
this.InvalidateArrange();
}
else
{
Point b = transform.Transform(new Point(this.ActualWidth, this.ActualHeight));
Interop.ThumbnailProperties props = new Interop.ThumbnailProperties();
props.Visible = true;
props.Destination = new Interop.Rect(
(int)Math.Ceiling(a.X), (int)Math.Ceiling(a.Y),
(int)Math.Ceiling(b.X), (int)Math.Ceiling(b.Y));
props.Flags = Interop.ThumbnailFlags.Visible | Interop.ThumbnailFlags.RectDestination;
Interop.DwmUpdateThumbnailProperties(thumb, ref props);
}
}
}
private void UpdateThumbnail()
{
if (IntPtr.Zero != thumb)
{
Interop.ThumbnailProperties props = new Interop.ThumbnailProperties();
props.SourceClientAreaOnly = this.ClientAreaOnly;
props.Opacity = (byte)(255 * this.Opacity);
props.Flags = Interop.ThumbnailFlags.SourceClientAreaOnly | Interop.ThumbnailFlags.Opacity;
Interop.DwmUpdateThumbnailProperties(thumb, ref props);
}
}
// this is where the magic happens
private void Thumbnail_LayoutUpdated(object sender, EventArgs e)
{
if (IntPtr.Zero == thumb)
{
InitialiseThumbnail(this.Source);
}
if (IntPtr.Zero != thumb)
{
if (target.RootVisual == null || !target.RootVisual.IsAncestorOf(this))
{
//we are no longer in the visual tree
ReleaseThumbnail();
return;
}
GeneralTransform transform = TransformToAncestor(target.RootVisual);
Point a = transform.Transform(new Point(0, 0));
if (double.IsNaN(a.X))
{
this.InvalidateArrange();
}
else
{
Point b = transform.Transform(new Point(this.ActualWidth, this.ActualHeight));
Interop.ThumbnailProperties props = new Interop.ThumbnailProperties();
props.Visible = true;
props.Destination = new Interop.Rect(
(int)Math.Ceiling(a.X), (int)Math.Ceiling(a.Y),
(int)Math.Ceiling(b.X), (int)Math.Ceiling(b.Y));
props.Flags = Interop.ThumbnailFlags.Visible | Interop.ThumbnailFlags.RectDestination;
Interop.DwmUpdateThumbnailProperties(thumb, ref props);
}
}
}
private void InitialiseThumbnail(IntPtr source)
{
if (IntPtr.Zero != thumb)
{
// release the old thumbnail
ReleaseThumbnail();
}
if (IntPtr.Zero != source)
{
// find our parent hwnd
target = (HwndSource)HwndSource.FromVisual(this);
// if we have one, we can attempt to register the thumbnail
if (target != null && 0 == Interop.DwmRegisterThumbnail(target.Handle, source, out this.thumb))
{
Interop.ThumbnailProperties props = new Interop.ThumbnailProperties();
props.Visible = false;
props.SourceClientAreaOnly = this.ClientAreaOnly;
props.Opacity = (byte)(255 * this.Opacity);
props.Flags = Interop.ThumbnailFlags.Visible | Interop.ThumbnailFlags.SourceClientAreaOnly
| Interop.ThumbnailFlags.Opacity;
Interop.DwmUpdateThumbnailProperties(thumb, ref props);
}
}
}
