public void SetImageUpdateLayeredWindow(Bitmap image, int newOpacity = 255)
{
if (image == null)
{
return;
}
if (image.PixelFormat != PixelFormat.Format32bppArgb)
{
throw new ApplicationException("The bitmap must be 32ppp with alpha-channel.");
}
IntPtr screenDc = FormStyleAPI.GetDC(IntPtr.Zero);
IntPtr memDc = FormStyleAPI.CreateCompatibleDC(screenDc);
IntPtr hBitmap = IntPtr.Zero;
IntPtr oldBitmap = IntPtr.Zero;
try
{
hBitmap = image.GetHbitmap(Color.FromArgb(0));
oldBitmap = FormStyleAPI.SelectObject(memDc, hBitmap);
var size = new FormStyleAPI.Size {
cx = image.Width, cy = image.Height
};
var pointSource = new FormStyleAPI.Point {
x = 0, y = 0
};
var topPos = new FormStyleAPI.Point {
x = Left, y = Top
};
var blend = new FormStyleAPI.BLENDFUNCTION
{
BlendOp = FormStyleAPI.AC_SRC_OVER,
BlendFlags = 0,
SourceConstantAlpha = (byte)newOpacity,
AlphaFormat = FormStyleAPI.AC_SRC_ALPHA
};
FormStyleAPI.UpdateLayeredWindow(Handle, screenDc, ref topPos, ref size, memDc, ref pointSource, 0, ref blend, FormStyleAPI.ULW_ALPHA);
}
finally
{
FormStyleAPI.ReleaseDC(IntPtr.Zero, screenDc);
if (hBitmap != IntPtr.Zero)
{
FormStyleAPI.SelectObject(memDc, oldBitmap);
FormStyleAPI.DeleteObject(hBitmap);
}
FormStyleAPI.DeleteDC(memDc);
}
}
public void SetBits()
{
if (BackgroundImage != null)
{
//绘制绘图层背景
Bitmap bitmap = new Bitmap(BackgroundImage, base.Width, base.Height);
if (!Image.IsCanonicalPixelFormat(bitmap.PixelFormat) || !Image.IsAlphaPixelFormat(bitmap.PixelFormat))
{
throw new ApplicationException("图片必须是32位带Alhpa通道的图片。");
}
IntPtr oldBits = IntPtr.Zero;
IntPtr screenDC = FormStyleAPI.GetDC(IntPtr.Zero);
IntPtr hBitmap = IntPtr.Zero;
IntPtr memDc = FormStyleAPI.CreateCompatibleDC(screenDC);
try
{
FormStyleAPI.Point topLoc = new FormStyleAPI.Point(Left, Top);
FormStyleAPI.Size bitMapSize = new FormStyleAPI.Size(Width, Height);
FormStyleAPI.BLENDFUNCTION blendFunc = new FormStyleAPI.BLENDFUNCTION();
FormStyleAPI.Point srcLoc = new FormStyleAPI.Point(0, 0);
hBitmap = bitmap.GetHbitmap(Color.FromArgb(0));
oldBits = FormStyleAPI.SelectObject(memDc, hBitmap);
blendFunc.BlendOp = FormStyleAPI.AC_SRC_OVER;
blendFunc.SourceConstantAlpha = Byte.Parse(((int)(Main.Opacity * 255)).ToString());
blendFunc.AlphaFormat = FormStyleAPI.AC_SRC_ALPHA;
blendFunc.BlendFlags = 0;
FormStyleAPI.UpdateLayeredWindow(Handle, screenDC, ref topLoc, ref bitMapSize, memDc, ref srcLoc, 0, ref blendFunc, FormStyleAPI.ULW_ALPHA);
}
finally
{
if (hBitmap != IntPtr.Zero)
{
FormStyleAPI.SelectObject(memDc, oldBits);
FormStyleAPI.DeleteObject(hBitmap);
}
FormStyleAPI.ReleaseDC(IntPtr.Zero, screenDC);
FormStyleAPI.DeleteDC(memDc);
bitmap.Dispose();
}
}
}
