目前我的应用程序使用了user32.dll中的UpdateLayeredWindow()函数并且它运行良好，但我试图用UpdateLayeredWindowIndirect()调用来替换它以利用{{1} UPDATELAYEREDWINDOWINFO结构中的标志。
目前，UpdateLayeredWindow() P / invoke按如下方式完成：
nameField = JOptionPane.showInputDialog(null, "Enter Username(Default is 000000");
变量类型与委托匹配，函数调用按预期工作。
然后我尝试用UpdateLayeredWindowIndirect()替换呼叫，如下所示：
prcDirty在控制台上，我收到消息：[DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
public static extern bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref Point pptDst,
ref Size psize, IntPtr hdcSrc, ref Point pprSrc, int crKey,
ref BLENDFUNCTION pblend, BlendFlags dwFlags);
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct BLENDFUNCTION {
public byte BlendOp;
public byte BlendFlags;
public byte SourceConstantAlpha;
public byte AlphaFormat;
}
public enum BlendFlags : uint {
None = 0x00,
ULW_COLORKEY = 0x01,
ULW_ALPHA = 0x02,
ULW_OPAQUE = 0x04
}
//UpdateLayeredWindow() called here
public UpdateMethodHere() {
UpdateLayeredWindow(handle, hdcWindow, ref dest, ref size, hDC, ref src, 0, ref blend,
BlendFlags.ULW_ALPHA);
}
。我尝试将SIZE结构变量更改为[DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
public static extern bool UpdateLayeredWindowIndirect(IntPtr hwnd,
ref UPDATELAYEREDWINDOWINFO updateInfo);
[StructLayout(LayoutKind.Sequential)]
public struct UPDATELAYEREDWINDOWINFO {
public static readonly int Size = Marshal.SizeOf(typeof(UPDATELAYEREDWINDOWINFO));
public int cbSize;
public IntPtr hdcDst;
public POINT pptDst;
public SIZE psize;
public IntPtr hdcSrc;
public POINT pptSrc;
public int crKey;
//BLENDFUNCTION is the same as in the first part of the question
public BLENDFUNCTION pblend;
//BlendFlags is the same as in the first part of the question
public BlendFlags dwFlags;
public RECT prcDirty;
}
[StructLayout(LayoutKind.Sequential)]
public struct POINT {
public int X;
public int Y;
public POINT(int x, int y) {
this.X = x;
this.Y = y;
}
}
[StructLayout(LayoutKind.Sequential)]
public struct SIZE {
public long cx;
public long cy;
public SIZE(long width, long height) {
cx = width;
cy = height;
}
}
[StructLayout(LayoutKind.Sequential)]
public struct RECT {
public int left;
public int top;
public int right;
public int bottom;
public RECT(int left, int top, int width, int height) {
this.left = left;
this.top = top;
right = left + width;
bottom = top + height;
}
}
//UpdateLayeredWindowIndirect() called here
public UpdateMethodHere() {
UPDATELAYEREDWINDOWINFO info = new UPDATELAYEREDWINDOWINFO() {
//the variables on the right-hand size used here are the same as the
//ones used in part 1 of the question
cbSize = UPDATELAYEREDWINDOWINFO.Size,
hdcDst = hdcWindow,
pptDst = new POINT(dest.X, dest.Y),
psize = new SIZE(size.Width, size.Height),
hdcSrc = hDC,
pptSrc = new POINT(src.X, src.Y),
crKey = 0,
pblend = blend,
dwFlags = BlendFlags.ULW_ALPHA,
prcDirty = new RECT(src.X, src.Y, size.Width, size.Height)
};
UpdateLayeredWindowIndirect(handle, ref info);
Console.WriteLine(new Win32Exception(Marshal.GetLastWin32Error()).Message);
}
类型而不是The parameter is incorrect，但我在控制台中收到int消息。
是否有人能够发现与UpdateLayeredWindowIndirect() P / invoke相关的委托和/或结构签名不正确的内容？