internal static extern bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref POINT pptDst, ref SIZE psize, IntPtr hdcSrc, ref POINT pprSrc, int crKey, ref BLENDFUNCTION pblend, int dwFlags);
internal static extern bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref POINT pptDst, ref SIZE psize, IntPtr hdcSrc, ref POINT pprSrc, int crKey, ref BLENDFUNCTION pblend, int dwFlags);
private void UpdateLayeredWindow(Point point, Size size, byte alpha)
{
using (Bitmap bmp = new Bitmap(size.Width, size.Height, PixelFormat.Format32bppArgb))
{
using (Graphics g = Graphics.FromImage(bmp))
{
// Paint the window on the bitmap
Rectangle bounds = new Rectangle(0, 0, size.Width, size.Height);
// First non-client area
OnNCPaint(new NcPaintEventArgs(g, bounds));
// Adjust graphics and paint client area
using (Region region = g.Clip)
{
Rectangle rectClient = GetClientRectangle(bounds);
region.Intersect(rectClient);
g.Clip = region;
g.TranslateTransform(rectClient.Left, rectClient.Top);
OnPaint(new PaintEventArgs(g, GetClientRectangle(bounds)));
}
SIZE size1;
POINT point1;
POINT point2;
IntPtr ptr1 = User32.GetDC(IntPtr.Zero);
IntPtr ptr2 = Gdi32.CreateCompatibleDC(ptr1);
IntPtr ptr3 = bmp.GetHbitmap(Color.FromArgb(0));
IntPtr ptr4 = Gdi32.SelectObject(ptr2, ptr3);
size1.cx = size.Width;
size1.cy = size.Height;
point1.x = point.X;
point1.y = point.Y;
point2.x = 0;
point2.y = 0;
BLENDFUNCTION blendfunction1 = new BLENDFUNCTION
{
BlendOp = 0,
BlendFlags = 0,
SourceConstantAlpha = alpha,
AlphaFormat = 1
};
User32.UpdateLayeredWindow(Handle, ptr1, ref point1, ref size1, ptr2, ref point2, 0, ref blendfunction1, 2);
Gdi32.SelectObject(ptr2, ptr4);
User32.ReleaseDC(IntPtr.Zero, ptr1);
Gdi32.DeleteDC(ptr2);
}
}
}