public static void SetBitmap(Bitmap bitmap, Form frm)
{
// retrieve current screen device context
IntPtr screenDc = NativeMethods.GetDC(IntPtr.Zero);
// create a memory device context compatible with the screen
IntPtr compatibleMemoryDc = NativeMethods.CreateCompatibleDC(screenDc);
IntPtr hgdiBitmap = IntPtr.Zero;
IntPtr hgdiOldBitmap = IntPtr.Zero;
try
{
hgdiBitmap = bitmap.GetHbitmap(Color.FromArgb(0));
// select a bitmap object into the memory device context created above
hgdiOldBitmap = NativeMethods.SelectObject(compatibleMemoryDc, hgdiBitmap);
// ++ prepare structures we need in order to call UpdateLayeredWindow ++
NativeMethods.SizeStruct size = new NativeMethods.SizeStruct()
{
X = bitmap.Width,
Y = bitmap.Height
};
NativeMethods.PointStruct sourcePoint = new NativeMethods.PointStruct();
NativeMethods.PointStruct topPoint = new NativeMethods.PointStruct()
{
X = frm.Left,
Y = frm.Top
};
NativeMethods.BlendFunctionStruct blend = new NativeMethods.BlendFunctionStruct()
{
BlendOp = 255 /* opacity */,
BlendFlags = 0x00 /* AC_SRC_OVER */,
AlphaFormat = 0x01 /* AC_SRC_ALPHA */,
SourceConstantAlpha = byte.MaxValue
};
frm.Invoke((MethodInvoker) delegate
{
NativeMethods.UpdateLayeredWindow(frm.Handle, screenDc, ref topPoint, ref size, compatibleMemoryDc,
ref sourcePoint, 0, ref blend, 2 /* ULW_ALPHA */);
});
}
finally
{
if (screenDc != IntPtr.Zero)
{
NativeMethods.ReleaseDC(IntPtr.Zero, screenDc);
}
if (hgdiBitmap != IntPtr.Zero)
{
NativeMethods.SelectObject(compatibleMemoryDc, hgdiOldBitmap);
NativeMethods.DeleteObject(hgdiBitmap);
}
NativeMethods.DeleteDC(compatibleMemoryDc);
}
}
internal void SetBitmap(Bitmap bitmap, int alpha = 100)
{
IntPtr screenDc = NativeMethods.GetDC(IntPtr.Zero);
IntPtr compatibleMemoryDc = NativeMethods.CreateCompatibleDC(screenDc);
IntPtr hgdiBitmap = IntPtr.Zero;
IntPtr hgdiOldBitmap = IntPtr.Zero;
try
{
try
{
hgdiBitmap = bitmap.GetHbitmap(Color.FromArgb(0));
}
catch
{ return; }
hgdiOldBitmap = NativeMethods.SelectObject(compatibleMemoryDc, hgdiBitmap);
NativeMethods.SizeStruct size = new NativeMethods.SizeStruct()
{
X = bitmap.Width,
Y = bitmap.Height
};
NativeMethods.PointStruct sourcePoint = new NativeMethods.PointStruct();
NativeMethods.PointStruct topPoint = new NativeMethods.PointStruct()
{
X = Left,
Y = Top
};
NativeMethods.BlendFunctionStruct blend = new NativeMethods.BlendFunctionStruct()
{
BlendOp = (byte)(255 * alpha / 100d) /* opacity */,
BlendFlags = 0x00 /* AC_SRC_OVER */,
AlphaFormat = 0x01 /* AC_SRC_ALPHA */,
SourceConstantAlpha = (byte)(255 * alpha / 100d)
};
try
{
Invoke((MethodInvoker) delegate
{
NativeMethods.UpdateLayeredWindow(Handle, screenDc, ref topPoint, ref size, compatibleMemoryDc,
ref sourcePoint, 0, ref blend, 2 /* ULW_ALPHA */);
});
}
catch { }
}
finally
{
if (screenDc != IntPtr.Zero)
{
NativeMethods.ReleaseDC(IntPtr.Zero, screenDc);
}
if (hgdiBitmap != IntPtr.Zero)
{
NativeMethods.SelectObject(compatibleMemoryDc, hgdiOldBitmap);
NativeMethods.DeleteObject(hgdiBitmap);
}
NativeMethods.DeleteDC(compatibleMemoryDc);
}
}
