QT全局热键

在网上找了很长时间，大家都提到了一个QT全局热键库（qxtglobalshortcut），支持跨平台。在这篇文章中，我将只展示出windows平台下全局热键的设置。

这里提供的方法是在MyGlobalShortCut里面完成Windows的API封装，并在main.cpp中使用。

直接上代码：

MyWinEventFilter类：

class MyWinEventFilter :public QAbstractNativeEventFilter

{

public:

[code]MyWinEventFilter(MyGlobalShortCut *shortcut);
~MyWinEventFilter();
virtual bool nativeEventFilter(const QByteArray &eventType, void *message, long*);

private:

[code]MyGlobalShortCut *m_shortcut;

};

MyWinEventFilter::MyWinEventFilter(MyGlobalShortCut* shortcut) :m_shortcut(shortcut)

{}

MyWinEventFilter::~MyWinEventFilter()

{}

bool MyWinEventFilter::nativeEventFilter(const QByteArray &eventType, void message, long)

{

[code]MSG *msg = static_cast(message);//static_cast<MSG*>(message)(把这段替换)
if (msg->message == WM_HOTKEY)
{
    const quint32 keycode = HIWORD(msg->lParam);
    const quint32 modifiers = LOWORD(msg->lParam);
    bool res = m_shortcut->shortcuts.value(qMakePair(keycode, modifiers));
    if (res)
    {
        m_shortcut->activateShortcut();
        return true;
    }
}
return false;

}

MyGlobalShortCut类：

class MyGlobalShortCut :public QObject

{

Q_OBJECT

public:

[code]MyGlobalShortCut(QKeySequence key);
~MyGlobalShortCut();
void activateShortcut();
bool registerHotKey();
bool unregisterHotKey();
QHash<QPair<quint32, quint32>, MyGlobalShortCut*> shortcuts;

private:

[code]QApplication *m_app;
MyWinEventFilter *m_filter;
QKeySequence m_key;
Qt::Key key;
Qt::KeyboardModifiers mods;
static quint32 nativeKeycode(Qt::Key keycode);
static quint32 nativeModifiers(Qt::KeyboardModifiers modifiers);

signals:

[code]void activated();

};

MyGlobalShortCut::MyGlobalShortCut(QKeySequence key)

{

[code]m_key = QKeySequence(key);
m_filter = new MyWinEventFilter(this);
m_app->installNativeEventFilter(m_filter);
registerHotKey();

}

MyGlobalShortCut::~MyGlobalShortCut()

{

[code]unregisterHotKey();

}

void MyGlobalShortCut::activateShortcut()

{

[code]emit activated();

}

bool MyGlobalShortCut::registerHotKey()

{

[code]Qt::KeyboardModifiers allMods = Qt::ShiftModifier | Qt::ControlModifier | Qt::AltModifier | Qt::MetaModifier;
key = (m_key.isEmpty() ? Qt::Key(0) : Qt::Key((m_key[0] ^ allMods) & m_key[0]));
mods = m_key.isEmpty() ? Qt::KeyboardModifiers(0) : Qt::KeyboardModifiers(m_key[0] & allMods);
const quint32 nativeKey = nativeKeycode(key);
const quint32 nativeMods = nativeModifiers(mods);

shortcuts.insert(qMakePair(nativeKey, nativeMods), this);
return RegisterHotKey(0, nativeMods ^ nativeKey, nativeMods, nativeKey);

}

bool MyGlobalShortCut::unregisterHotKey()

{

[code]return UnregisterHotKey(0, (quint32)nativeModifiers(mods) ^ (quint32)nativeKeycode(key));

}

quint32 MyGlobalShortCut::nativeKeycode(Qt::Key key)

{

[code]switch (key)
{
case Qt::Key_Escape:
    return VK_ESCAPE;
case Qt::Key_Tab:
case Qt::Key_Backtab:
    return VK_TAB;
case Qt::Key_Backspace:
    return VK_BACK;
case Qt::Key_Return:
case Qt::Key_Enter:
    return VK_RETURN;
case Qt::Key_Insert:
    return VK_INSERT;
case Qt::Key_Delete:
    return VK_DELETE;
case Qt::Key_Pause:
    return VK_PAUSE;
case Qt::Key_Print:
    return VK_PRINT;
case Qt::Key_Clear:
    return VK_CLEAR;
case Qt::Key_Home:
    return VK_HOME;
case Qt::Key_End:
    return VK_END;
case Qt::Key_Left:
    return VK_LEFT;
case Qt::Key_Up:
    return VK_UP;
case Qt::Key_Right:
    return VK_RIGHT;
case Qt::Key_Down:
    return VK_DOWN;
case Qt::Key_PageUp:
    return VK_PRIOR;
case Qt::Key_PageDown:
    return VK_NEXT;
case Qt::Key_F1:
    return VK_F1;
case Qt::Key_F2:
    return VK_F2;
case Qt::Key_F3:
    return VK_F3;
case Qt::Key_F4:
    return VK_F4;
case Qt::Key_F5:
    return VK_F5;
case Qt::Key_F6:
    return VK_F6;
case Qt::Key_F7:
    return VK_F7;
case Qt::Key_F8:
    return VK_F8;
case Qt::Key_F9:
    return VK_F9;
case Qt::Key_F10:
    return VK_F10;
case Qt::Key_F11:
    return VK_F11;
case Qt::Key_F12:
    return VK_F12;
case Qt::Key_F13:
    return VK_F13;
case Qt::Key_F14:
    return VK_F14;
case Qt::Key_F15:
    return VK_F15;
case Qt::Key_F16:
    return VK_F16;
case Qt::Key_F17:
    return VK_F17;
case Qt::Key_F18:
    return VK_F18;
case Qt::Key_F19:
    return VK_F19;
case Qt::Key_F20:
    return VK_F20;
case Qt::Key_F21:
    return VK_F21;
case Qt::Key_F22:
    return VK_F22;
case Qt::Key_F23:
    return VK_F23;
case Qt::Key_F24:
    return VK_F24;
case Qt::Key_Space:
    return VK_SPACE;
case Qt::Key_Asterisk:
    return VK_MULTIPLY;
case Qt::Key_Plus:
    return VK_ADD;
case Qt::Key_Comma:
    return VK_SEPARATOR;
case Qt::Key_Minus:
    return VK_SUBTRACT;
case Qt::Key_Slash:
    return VK_DIVIDE;

    // numbers
case Qt::Key_0:
case Qt::Key_1:
case Qt::Key_2:
case Qt::Key_3:
case Qt::Key_4:
case Qt::Key_5:
case Qt::Key_6:
case Qt::Key_7:
case Qt::Key_8:
case Qt::Key_9:
    return key;

    // letters
case Qt::Key_A:
case Qt::Key_B:
case Qt::Key_C:
case Qt::Key_D:
case Qt::Key_E:
case Qt::Key_F:
case Qt::Key_G:
case Qt::Key_H:
case Qt::Key_I:
case Qt::Key_J:
case Qt::Key_K:
case Qt::Key_L:
case Qt::Key_M:
case Qt::Key_N:
case Qt::Key_O:
case Qt::Key_P:
case Qt::Key_Q:
case Qt::Key_R:
case Qt::Key_S:
case Qt::Key_T:
case Qt::Key_U:
case Qt::Key_V:
case Qt::Key_W:
case Qt::Key_X:
case Qt::Key_Y:
case Qt::Key_Z:
    return key;

default:
    return 0;
}

}

quint32 MyGlobalShortCut::nativeModifiers(Qt::KeyboardModifiers modifiers)

{

[code]// MOD_ALT, MOD_CONTROL, (MOD_KEYUP), MOD_SHIFT, MOD_WIN
quint32 native = 0;
if (modifiers & Qt::ShiftModifier)
    native |= MOD_SHIFT;
if (modifiers & Qt::ControlModifier)
    native |= MOD_CONTROL;
if (modifiers & Qt::AltModifier)
    native |= MOD_ALT;
if (modifiers & Qt::MetaModifier)
    native |= MOD_WIN;
return native;

}

//////////////////////////////////////////////////////////////////////////////////////////////

上面是类的封装，下面是使用：

在main()函数中加入：

QKeySequence keySequence=QKeySequence(tr(“ALT+A”));//设置快捷键ALT+A

MyGlobalShortCut *shortcut=new MyGlobalShortCut(keySequence);

connect(shortcut,SIGNAL(activated()),this,SLOT(onActivated()));

onActivated()

{

//全局热键被激活之后要做的事

}

这只是针对windows系统的实现，由于工作中现在只涉及windows，其他系统类似，主要就是实现nativeEventFilter（）方法。

/////////////////////////////////////////////////////////////////////////////////////////////

(全文完)