protected virtual void UpdateLayeredWindow(byte alpha)
{
var bitmap = (Bitmap)BackgroundImage;
IntPtr hdcScreen = NativeMethods.GetDC(new HandleRef(this, IntPtr.Zero));
IntPtr hdcMemory = NativeMethods.CreateCompatibleDC(new HandleRef(this, hdcScreen));
IntPtr hBitmap = bitmap.GetHbitmap(Color.FromArgb(0));
IntPtr hOldBitmap = NativeMethods.SelectObject(new HandleRef(this, hdcMemory), new HandleRef(this, hBitmap));
var size = new NativeMethods.SIZESTRUCT(bitmap.Width, bitmap.Height);
var pointSource = new NativeMethods.POINTSTRUCT(0, 0);
var topPos = new NativeMethods.POINTSTRUCT(Left, Top);
var blend = new NativeMethods.BLENDFUNCTION();
blend.BlendOp = 0;
blend.BlendFlags = 0;
blend.SourceConstantAlpha = alpha;
blend.AlphaFormat = 1;
NativeMethods.UpdateLayeredWindow(handle, hdcScreen, ref topPos, ref size, hdcMemory, ref pointSource, 0,
ref blend, 0x00000002);
NativeMethods.ReleaseDC(new HandleRef(this, IntPtr.Zero), new HandleRef(this, hdcScreen));
if (hBitmap != IntPtr.Zero)
{
NativeMethods.SelectObject(new HandleRef(this, hdcMemory), new HandleRef(this, hOldBitmap));
NativeMethods.DeleteObject(new HandleRef(this, hBitmap));
}
NativeMethods.DeleteDC(new HandleRef(this, hdcMemory));
}
public void SetBits()
{
Bitmap image = new Bitmap(this.m_HostForm.Width + (m_Config.ShadowWidth * 2), this.m_HostForm.Height + (m_Config.ShadowWidth * 2));
Graphics g = Graphics.FromImage(image);
g.SmoothingMode = SmoothingMode.HighQuality;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
this.DrawShadow(g);
if (Image.IsCanonicalPixelFormat(image.PixelFormat) && Image.IsAlphaPixelFormat(image.PixelFormat))
{
IntPtr zero = IntPtr.Zero;
//diff
//IntPtr dC = NativeMethods.GetDC(new HandleRef(null, IntPtr.Zero));
IntPtr dC = NativeMethods.GetDC(IntPtr.Zero);
IntPtr hgdiobj = IntPtr.Zero;
//diff
//IntPtr hdc = NativeMethods.CreateCompatibleDC(new HandleRef(null, dC));
IntPtr hdc = NativeMethods.CreateCompatibleDC(dC);
try
{
NativeMethods.POINTSTRUCT pptDst = new NativeMethods.POINTSTRUCT(base.Left, base.Top);
NativeMethods.SIZESTRUCT psize = new NativeMethods.SIZESTRUCT(base.Width, base.Height);
NativeMethods.BLENDFUNCTION pblend = new NativeMethods.BLENDFUNCTION();
NativeMethods.POINTSTRUCT pprSrc = new NativeMethods.POINTSTRUCT(0, 0);
hgdiobj = image.GetHbitmap(Color.FromArgb(0));
zero = NativeMethods.SelectObject(hdc, hgdiobj);
pblend.BlendOp = 0;
pblend.SourceConstantAlpha = byte.Parse("255");
pblend.AlphaFormat = 1;
pblend.BlendFlags = 0;
NativeMethods.UpdateLayeredWindow(base.Handle, dC, ref pptDst, ref psize, hdc, ref pprSrc, 0, ref pblend, 2);
return;
}
finally
{
if (hgdiobj != IntPtr.Zero)
{
NativeMethods.SelectObject(hdc, zero);
NativeMethods.DeleteObject(hgdiobj);
}
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。");
}
