上接 弹出窗口杀手(上)

注册系统热键

系统热键用在像弹出窗口杀手这种应用程序非常有用, Ctrl+Shift+J是缺省热键.
 
说道实现,我们继续用RegisterHotkey(HWND hWnd, int id, UINT fsModifiers, UINT vkey). 完成,代码如下:

public void SetHotKey(Keys c, bool bCtrl, bool bShift, bool bAlt, bool bWindows)

{

    m_hotkey = c;

    m_ctrlhotkey = bCtrl;

    m_shifthotkey = bShift;

    m_althotkey = bAlt;

    m_winhotkey = bWindows;

    // update hotkey

    NativeWIN32.KeyModifiers modifiers = NativeWIN32.KeyModifiers.None;

    if (m_ctrlhotkey)

        modifiers |= NativeWIN32.KeyModifiers.Control;

    if (m_shifthotkey)

        modifiers |= NativeWIN32.KeyModifiers.Shift;

    if (m_althotkey)

        modifiers |= NativeWIN32.KeyModifiers.Alt;

    if (m_winhotkey)

        modifiers |= NativeWIN32.KeyModifiers.Windows;

    NativeWIN32.RegisterHotKey(Handle, 100, modifiers, m_hotkey); //Keys.J);

}

一般的,注册热键要一下几步

/* ------- using HOTKEYs in a C# application -------

   -- code snippet by James J Thompson --

在Form的load 中 : Ctrl+Shift+J

         bool success = RegisterHotKey(Handle, 

                                      100, 

                                      KeyModifiers.Control | KeyModifiers.Shift, 

                                      Keys.J);

 在 form的closing中 :

         UnregisterHotKey(Handle, 100);

 如何处理热键 :

     protected override void WndProc( ref Message m )

     {   

         const int WM_HOTKEY = 0x0312;       

         switch(m.Msg)     

          {       

             case WM_HOTKEY:         

                 MessageBox.Show("Hotkey pressed");            

                 ProcessHotkey();

                 break;      

         }         

         base.WndProc(ref m );

     }

public class NativeWIN32

{

    [DllImport("user32.dll", SetLastError=true)]

    public static extern bool RegisterHotKey( IntPtr hWnd, // handle to window    

                                              int id, // hot key identifier    

                                              KeyModifiers fsModifiers,  // key-modifier options    

                                              Keys vk            // virtual-key code    

    ); 

    [DllImport("user32.dll", SetLastError=true)]

    public static extern bool UnregisterHotKey( IntPtr hWnd, // handle to window    

                                                int id      // hot key identifier    

    );

    [Flags()]

    public enum KeyModifiers

    {  

        None = 0,

        Alt = 1,    

        Control = 2,    

        Shift = 4,    

        Windows = 8

    }

}

------- using HOTKEYs in a C# application ------- */

当我们按下热键以后,流程是这样:首先用HWND GetForegroundWindow()来得到窗体,然后要抓出窗体的标题, GetWindowText(HWND hwnd, /*out*/LPTSTR lpString, int nMaxCount). 具体如下:

protected void ProcessHotkey()

{

    IntPtr hwnd = NativeWIN32.GetForegroundWindow();

    if (!hwnd.Equals(IntPtr.Zero))

    {

        NativeWIN32.STRINGBUFFER sWindowTitle;

        NativeWIN32.GetWindowText(hwnd, out sWindowTitle, 256);

        if (sWindowTitle.szText.Length>0)

            AddWindowTitle( sWindowTitle.szText ); // add to the ListView (Form)

    }

}

演示程序: http://www.codeproject.com/useritems/popupkiller/popupkiller_demo_update.zip

(全文完)