c# - 无法将 WM_INPUTLANGCHANGEREQUEST 发送到某些控件

Question

我正在研究(又一个)keyboard layout switcher并在 Skype 窗口(win7 x64 上的 6.22 版)中遇到了奇怪的麻烦。 Any combinations GetForegroundWindow()/GetFocus()/GetParentWindow() 不会成功更改布局仅在消息输入内，更奇怪的是，仅当输入多个字符时。其他情况下工作得非常好，除了 wpf 应用程序拒绝服从没有 focusedHandle 的东西。

public static void SetNextKeyboardLayout()
    {
        IntPtr hWnd = GetForegroundWindow();
        uint processId;
        uint activeThreadId = GetWindowThreadProcessId(hWnd, out processId);
        uint currentThreadId = GetCurrentThreadId();

        AttachThreadInput(activeThreadId, currentThreadId, true);
        IntPtr focusedHandle = GetFocus();
        AttachThreadInput(activeThreadId, currentThreadId, false);

        PostMessage(focusedHandle == IntPtr.Zero ? hWnd : focusedHandle, WM_INPUTLANGCHANGEREQUEST, INPUTLANGCHANGE_FORWARD, HKL_NEXT);
    }

我是 winapi 的新手，所以任何帮助都将不胜感激，谢谢。

Answer 1

在分解了一些工作产品后，我发现我已经接近正确的算法，看起来像这样:

public static void SetNextKeyboardLayout()
{
    IntPtr hWnd = IntPtr.Zero;
    var threadId = GetWindowThreadProcessId(GetForegroundWindow(), IntPtr.Zero);
    var currentThreadId = GetCurrentThreadId();

    var info = new GUITHREADINFO();
    info.cbSize = Marshal.SizeOf(info);
    var success = GetGUIThreadInfo(threadId, ref info);

    // target = hwndCaret || hwndFocus || (AttachThreadInput + GetFocus) || hwndActive || GetForegroundWindow
    AttachThreadInput(threadId, currentThreadId, true);
    IntPtr focusedHandle = GetFocus();
    AttachThreadInput(threadId, currentThreadId, false);
    if (success)
    {
        if (info.hwndCaret != IntPtr.Zero) { hWnd = info.hwndCaret; }
        else if (info.hwndFocus != IntPtr.Zero) { hWnd = info.hwndFocus; }
        else if (focusedHandle != IntPtr.Zero) { hWnd = focusedHandle; }
        else if (info.hwndActive != IntPtr.Zero) { hWnd = info.hwndActive; }
    }
    else
    {
        hWnd = focusedHandle;
    }
    if (hWnd == IntPtr.Zero) { hWnd = GetForegroundWindow(); }

    PostMessage(hWnd, WM_INPUTLANGCHANGEREQUEST, INPUTLANGCHANGE_FORWARD, HKL_NEXT);
}

但问题不在于找到 PostMessage 目标 hWnd，而在于 Skype 的输入处理。我通过在 WM_INPUTLANGCHANGEREQUEST 之前添加一个微小的延迟来解决这个问题，这样 Skype 就可以正确处理发送给它的所有输入。现在我必须立即开始工作，但这是另一回事了。