C# 全局键和 SetForegroundWindow

Question

我正在使用 C# 应用来监听全局组合键 (ctrl+F9)，这会将特定窗口置于最前面。

这是我用来将窗口置于最前面的代码，它仅在由 Button 事件触发时有效:

    private void button3_Click(object sender, EventArgs e)
    {
        SetForegroundWindow(ptrActiveWindow.ToInt32());
        ShowWindowAsync(ptrActiveWindow, SW_RESTORE);
    }

对于 Hook ，我使用了取自 http://www.codeproject.com/KB/cs/CSLLKeyboardHook.aspx 的类，此处完整列出:

http://code.google.com/p/code-commenter/source/browse/trunk/key+preview/globalKeyboardHook.cs?spec=svn3&r=3

每当我在 CTRL KeyDown 之后和 CTRL KeyUp 之前(仍然按下 CTRL)发生 F9 KeyUp 事件时，我调用我的方法:

    private void restore(IntPtr hWnd)
    {

      IntPtr ptrCurrentActiveWindow = GetForegroundWindow(); //comment line
      ShowWindowAsync(ptrCurrentActiveWindow, SW_MINIMIZE); //comment line

        ShowWindowAsync(hWnd, SW_RESTORE);
        SetFocus(hWnd);
        SetForegroundWindow(hWnd.ToInt32());

    }

这什么都不做。我的窗口在后台激活(我可以看到它在任务栏中闪烁)，但没有恢复。

我可以解决这个问题的唯一方法是使用注释代码:最小化当前事件的窗口，然后恢复我想看到的窗口。

感谢所有帮助，谢谢。

全局热键，工作版本:

    private void Form1_Load(object sender, EventArgs e)
    {
        string atomName = Thread.CurrentThread.ManagedThreadId.ToString("X8") + this.GetType().FullName;
        short HotkeyID = GlobalAddAtom(atomName);
        if (!RegisterHotKey(this.Handle, HotkeyID, (uint)GlobalHotkeys.MOD_CONTROL, (uint)Keys.D5))
            listBox.Items.Add("failed: " + "unable to register hotkey. Error: " + Marshal.GetLastWin32Error().ToString());
        else
            listBox.Items.Add("succeeded adding hotkey id"+(uint)Keys.D5);
    }

    protected override void WndProc(ref Message m)
    {
        const int WM_HOTKEY = 0x0312;

        if (m.Msg == WM_HOTKEY)
        {
            if ((short)m.WParam==HotkeyID)
                listBox.Items.Add("Hotkey."+ (short)m.WParam);
        }
        base.WndProc(ref m);
    }

Answer 1

您的问题是您没有注册全局热键，而是使用了键盘钩子(Hook)。键盘 Hook 并非设计用作全局热键。

使用 RegisterHotKey函数代替。
检查此示例:http://www.pinvoke.net/default.aspx/user32.registerhotkey

您的直接问题是应用程序无法随时将自己置于前台。因为这对用户来说很烦人。它只能在特定事件期间这样做。就像应用程序启动或处理真正的全局热键时。

The system restricts which processes can set the foreground window. A process can set the foreground window only if one of the following conditions is true:

• The process is the foreground process.
• The process was started by the foreground process.
• The process received the last input event.
• There is no foreground process.
• The foreground process is being debugged.
• The foreground is not locked (see LockSetForegroundWindow).
• The foreground lock time-out has expired (see SPI_GETFOREGROUNDLOCKTIMEOUT in SystemParametersInfo).
• No menus are active.