Question

我有一个窗口句柄，我试图通过传入窗口的进程ID来调用GetGUIThreadInfo。我总是在调用GetGUIThreadInfo时收到错误“参数错误”，我可以找出原因。有人有这个工作吗？

[DllImport("user32.dll", SetLastError = true)]
public static extern bool GetGUIThreadInfo(unit hTreadID, ref GUITHREADINFO lpgui);

[DllImport("user32.dll")]
public static extern uint GetWindowThreadProcessId(unit hwnd, out uint lpdwProcessId);

[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
    public int iLeft;
    public int iTop;
    public int iRight;
    public int iBottom;
}

[StructLayout(LayoutKind.Sequential)]
public struct GUITHREADINFO
{
    public int cbSize;
    public int flags;
    public IntPtr hwndActive;
    public IntPtr hwndFocus;
    public IntPtr hwndCapture;
    public IntPtr hwndMenuOwner;
    public IntPtr hwndMoveSize;
    public IntPtr hwndCaret;
    public RECT rectCaret;
}

public static bool GetInfo(unit hwnd, out GUITHREADINFO lpgui)
{ 
    uint lpdwProcessId;
    GetWindowThreadProcessId(hwnd, out lpdwProcessId);

    lpgui = new GUITHREADINFO();
    lpgui.cbSize = Marshal.SizeOf(lpgui);

    return GetGUIThreadInfo(lpdwProcessId, ref lpgui); //<!- error here, returns false
}

Answer 1

我认为您在调用GetWindowThreadProcessId时使用了错误的值，如果查看文档here，您会看到第二个参数是进程ID（就像您'一样）我命名了它，但线程ID在返回值中。

换句话说，我认为你的代码应该是这样的（未经测试）：

public static bool GetInfo(unit hwnd, out GUITHREADINFO lpgui)
{ 
    uint lpdwProcessId;
    uint threadId = GetWindowThreadProcessId(hwnd, out lpdwProcessId);

    lpgui = new GUITHREADINFO();
    lpgui.cbSize = Marshal.SizeOf(lpgui);

    return GetGUIThreadInfo(threadId, ref lpgui); 
}

如何在c＃中调用GetGUIThreadInfo

1 个答案: