private void UpdateLayeredWindow(Rectangle rect)
{
// Cache the latest size and location
_showRect = rect;
// Must have a visible rectangle to render
if ((rect.Width > 0) && (rect.Height > 0))
{
// Draw onto a bitmap that is then used as the window display
Bitmap memoryBitmap = new Bitmap(rect.Width, rect.Height, PixelFormat.Format32bppArgb);
using (Graphics g = Graphics.FromImage(memoryBitmap))
{
// Perform actual painting onto the bitmap
Rectangle area = new Rectangle(0, 0, rect.Width, rect.Height);
using (RenderContext context = new RenderContext(null, g, area, _renderer))
{
_renderer.RenderGlyph.DrawDragDropDockingGlyph(context, _dragData, _paletteDragDrop, PaletteDragFeedback.Rounded);
}
// Get hold of the screen DC
IntPtr hDC = PI.GetDC(IntPtr.Zero);
// Create a memory based DC compatible with the screen DC
IntPtr memoryDC = PI.CreateCompatibleDC(hDC);
// Get access to the bitmap handle contained in the Bitmap object
IntPtr hBitmap = memoryBitmap.GetHbitmap(Color.FromArgb(0));
// Select this bitmap for updating the window presentation
IntPtr oldBitmap = PI.SelectObject(memoryDC, hBitmap);
// New window size
PI.SIZE ulwsize;
ulwsize.cx = rect.Width;
ulwsize.cy = rect.Height;
// New window position
PI.POINT topPos = new PI.POINT(rect.Left, rect.Top);
// Offset into memory bitmap is always zero
PI.POINT pointSource = new PI.POINT(0, 0);
// We want to make the entire bitmap opaque
PI.BLENDFUNCTION blend = new PI.BLENDFUNCTION
{
BlendOp = PI.AC_SRC_OVER,
BlendFlags = 0,
SourceConstantAlpha = 255,
AlphaFormat = PI.AC_SRC_ALPHA
};
// Tell operating system to use our bitmap for painting
PI.UpdateLayeredWindow(Handle, hDC, ref topPos, ref ulwsize,
memoryDC, ref pointSource, 0, ref blend,
PI.ULW_ALPHA);
// Put back the old bitmap handle
PI.SelectObject(memoryDC, oldBitmap);
// Cleanup resources
PI.ReleaseDC(IntPtr.Zero, hDC);
PI.DeleteObject(hBitmap);
PI.DeleteDC(memoryDC);
}
}
}
private void UpdateLayeredWindow(Rectangle rect)
{
// Cache the latest size and location
_showRect = rect;
// Must have a visible rectangle to render
if ((rect.Width > 0) && (rect.Height > 0))
{
// Draw onto a bitmap that is then used as the window display
Bitmap memoryBitmap = new Bitmap(rect.Width, rect.Height, PixelFormat.Format32bppArgb);
using (Graphics g = Graphics.FromImage(memoryBitmap))
{
// Perform actual painting onto the bitmap
Rectangle area = new Rectangle(0, 0, rect.Width, rect.Height);
using (RenderContext context = new RenderContext(null, g, area, _renderer))
_renderer.RenderGlyph.DrawDragDropDockingGlyph(context, _dragData, _paletteDragDrop, PaletteDragFeedback.Rounded);
// Get hold of the screen DC
IntPtr hDC = PI.GetDC(IntPtr.Zero);
// Create a memory based DC compatible with the screen DC
IntPtr memoryDC = PI.CreateCompatibleDC(hDC);
// Get access to the bitmap handle contained in the Bitmap object
IntPtr hBitmap = memoryBitmap.GetHbitmap(Color.FromArgb(0));
// Select this bitmap for updating the window presentation
IntPtr oldBitmap = PI.SelectObject(memoryDC, hBitmap);
// New window size
PI.SIZE ulwsize;
ulwsize.cx = rect.Width;
ulwsize.cy = rect.Height;
// New window position
PI.POINT topPos;
topPos.x = rect.Left;
topPos.y = rect.Top;
// Offset into memory bitmap is always zero
PI.POINT pointSource;
pointSource.x = 0;
pointSource.y = 0;
// We want to make the entire bitmap opaque
PI.BLENDFUNCTION blend = new PI.BLENDFUNCTION();
blend.BlendOp = (byte)PI.AC_SRC_OVER;
blend.BlendFlags = 0;
blend.SourceConstantAlpha = 255;
blend.AlphaFormat = (byte)PI.AC_SRC_ALPHA;
// Tell operating system to use our bitmap for painting
PI.UpdateLayeredWindow(Handle, hDC, ref topPos, ref ulwsize,
memoryDC, ref pointSource, 0, ref blend,
(int)PI.ULW_ALPHA);
// Put back the old bitmap handle
PI.SelectObject(memoryDC, oldBitmap);
// Cleanup resources
PI.ReleaseDC(IntPtr.Zero, hDC);
PI.DeleteObject(hBitmap);
PI.DeleteDC(memoryDC);
}
}
}
