public virtual void UpdateWindow(Bitmap bitmap, double opacity)
{
if (bitmap == null)
{
return;
}
if (Image.IsCanonicalPixelFormat(bitmap.PixelFormat) && Image.IsAlphaPixelFormat(bitmap.PixelFormat))
{
IntPtr zero = IntPtr.Zero;
IntPtr dC = NativeMethods.GetDC(IntPtr.Zero);
IntPtr hObj = IntPtr.Zero;
IntPtr hDC = NativeMethods.CreateCompatibleDC(dC);
try
{
Point pptDst = new Point(base.Left, base.Top);
Size psize = new Size(bitmap.Width, bitmap.Height);
Struct.BLENDFUNCTION pblend = new Struct.BLENDFUNCTION();
Point pptSrc = new Point(0, 0);
hObj = bitmap.GetHbitmap(Color.FromArgb(0));
zero = NativeMethods.SelectObject(hDC, hObj);
pblend.BlendOp = 0;
pblend.SourceConstantAlpha = (byte)((int)(255.0 * opacity));
pblend.AlphaFormat = 1;
pblend.BlendFlags = 0;
NativeMethods.UpdateWindow(base.Handle, dC, ref pptDst, ref psize, hDC, ref pptSrc, 0, ref pblend, 2);
return;
}
finally
{
if (hObj != IntPtr.Zero)
{
NativeMethods.SelectObject(hDC, zero);
NativeMethods.DeleteObject(hObj);
}
NativeMethods.ReleaseDC(IntPtr.Zero, dC);
NativeMethods.DeleteDC(hDC);
}
}
throw new ApplicationException("图片必须是32位带Alhpa通道的图片。");
}
private void method_0(IntPtr intptr_0, ref Point point_0, ref Size size_0, IntPtr intptr_1, ref Point point_1, ref Struct.BLENDFUNCTION blendfunction_0)
{
NativeMethods.UpdateWindow(base.Handle, intptr_0, ref point_0, ref size_0, intptr_1, ref point_1, 0, ref blendfunction_0, 2);
}