用于QTabWidget的PyQt鼠标事件

Question

我想检测QTabWidget上的鼠标中点击。我期待在QWidget上有一个与鼠标事件相关的信号，但我所看到的只是方法。

我是否需要子类化QTabWidget，然后重写所说的方法才能做我想做的事情，还是我错过了什么？

Answer 1

您可以安装在QTabBar事件过滤器（由QTabWidget.tabBar()返回）来接收和处理按下和释放事件，或子类QTabBar重新定义mousePressEvent和mouseReleaseEvent与QTabWidget.setTabBar()更换QTabWidget的QTabBar。使用事件过滤器

1. 示例：使用QTabBar子

   class MainWindow(QMainWindow): 
       def __init__(self): 
        super(QMainWindow,self).__init__() 
        self.tabWidget = QTabWidget(self) 
        self.setCentralWidget(self.tabWidget) 
        self.tabWidget.tabBar().installEventFilter(self) 
        self.tabWidget.tabBar().previousMiddleIndex = -1   
   
       def eventFilter(self, object, event): 
        if object == self.tabWidget.tabBar() and \ 
         event.type() in [QEvent.MouseButtonPress, 
             QEvent.MouseButtonRelease] and \ 
         event.button() == Qt.MidButton: 
         tabIndex = object.tabAt(event.pos()) 
         if event.type() == QEvent.MouseButtonPress: 
          object.previousMiddleIndex = tabIndex 
         else: 
          if tabIndex != -1 and tabIndex == object.previousMiddleIndex: 
           self.onTabMiddleClick(tabIndex)      
          object.previousMiddleIndex = -1       
         return True    
        return False 
   
       # function called with the index of the clicked Tab 
       def onTabMiddleClick(self, index): 
        pass 
   

2. 例子：

   class TabBar(QTabBar): 
       middleClicked = pyqtSignal(int) 
   
       def __init__(self): 
        super(QTabBar, self).__init__() 
        self.previousMiddleIndex = -1 
   
       def mousePressEvent(self, mouseEvent): 
        if mouseEvent.button() == Qt.MidButton: 
         self.previousIndex = self.tabAt(mouseEvent.pos()) 
        QTabBar.mousePressEvent(self, mouseEvent) 
   
       def mouseReleaseEvent(self, mouseEvent): 
        if mouseEvent.button() == Qt.MidButton and \ 
         self.previousIndex == self.tabAt(mouseEvent.pos()): 
         self.middleClicked.emit(self.previousIndex) 
        self.previousIndex = -1 
        QTabBar.mouseReleaseEvent(self, mouseEvent) 
   
   
   class MainWindow(QMainWindow): 
       def __init__(self): 
        super(QMainWindow,self).__init__() 
        self.tabWidget = QTabWidget(self) 
        self.setCentralWidget(self.tabWidget) 
   
        self.tabBar = TabBar() 
        self.tabWidget.setTabBar(self.tabBar) 
        self.tabBar.middleClicked.connect(self.onTabMiddleClick) 
   
       # function called with the index of the clicked Tab 
       def onTabMiddleClick(self, index): 
        pass 
   

（如果你想知道为什么有这么多的代码，例如一个简单的任务，点击被定义为新闻事件，然后在大致相同的地点发布事件，所以新闻的索引d选项卡必须与发布的选项卡相同）。