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我想在用户发布Ctrl+时调用一些自定义复制代码C。C之前释放时Ctrl，Qt 发送一个与 匹配的键事件QKeySequence::Copy。Ctrl之前释放时C，释放事件不匹配。

当 key release 事件出现时Ctrl，有没有办法查看是否C仍然被按住？

当我不Ctrl首先处理被释放时，事件会传递并进行常规复制，这正是我不希望发生的事情。

bool
MyWidget::eventFilter(QObject* object, QEvent* event)
{
   // the text edit box filters its events through here
   if (object == m_text_edit_box)
   {
      if (event->type() == QEvent::KeyPress)
      {
         QKeyEvent *key_event = static_cast<QKeyEvent*>(event);

         if (key_event->matches(QKeySequence::Copy))
         {
            // don't do anything and don't pass along event
            return true;
         }
      }
      else if (event->type() == QEvent::KeyRelease)
      {
         QKeyEvent *key_event = static_cast<QKeyEvent*>(event);

         if (key_event->matches(QKeySequence::Copy))
         {
            // we only get in here if 'c' is released before ctrl
            callCustomCopy();
            return true;
         }
      }
   }

   // pass along event
   return false;
}
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1 回答 1

2

您可以专门查询字母“C”和元键Ctrl，而不依赖于 key_even->matches()。当然，您可以在 keydown 事件上放置 eventfilter 的对象中存储 keydown 序列是否匹配副本的事实。

这（未经测试）可能对您有用，请注意静态变量应该是其中包含的类的成员变量，这在本示例的上下文中似乎更清楚。您想要完成的确切逻辑可能需要在事件之间传递更多状态信息。

bool MyWidget::eventFilter(QObject* object, QEvent* event)
{
  // Remember state between events
  static foundCopy = false;
  // the text edit box filters its events through here
  if (object == m_text_edit_box)
  {
    if (event->type() == QEvent::KeyPress)
    {
    QKeyEvent *key_event = static_cast<QKeyEvent*>(event);
      if (key_event->matches(QKeySequence::Copy))
      {
        foundCopy = true;
        // don't do anything and don't pass along event
        return true;
      }
      else
      {
        foundCopy = false;
        // This is another sequence, ignore and pass event
        // Note that this will trigger with ctrl+c+a and others

      }
    }
    else if (event->type() == QEvent::KeyRelease)
    {
      QKeyEvent *key_event = static_cast<QKeyEvent*>(event);
      if (foundCopy)
      {
        callCustomCopy();
        foundCopy = false;
        return true;
      }
      // This should keep the system copy from triggering
      if (key_event->matches(QKeySequence::Copy))
      {
        return true;
      }
    }
  }

   // pass along event
 return false;
}

另一种方法是收集当前按下的所有键的实际状态，然后在释放一个键时查看哪些键仍然被按下。

从 UI 的角度来看，请记住所有键盘操作都是在按下时执行的（例如，键入、Windows 粘贴），通常在释放时执行操作可能会使用户感到困惑，尤其是当操作有可见结果时。我无法从您的示例中看出您要完成什么。

于 2009-07-17T21:41:25.590 回答