在Qt中获取MouseMoveEvents [英] Getting MouseMoveEvents in Qt

问题描述

在我的程序中，我希望每当鼠标移动(即使它在另一个窗口上)时都调用mouseMoveEvent(QMouseEvent *事件).

In my program, I'd like to have mouseMoveEvent(QMouseEvent* event) called whenever the mouse moves (even when it's over another window).

现在，在我的mainwindow.cpp文件中，我有:

Right now, in my mainwindow.cpp file, I have:

void MainWindow::mouseMoveEvent(QMouseEvent* event) {
    qDebug() << QString::number(event->pos().x());
    qDebug() << QString::number(event->pos().y());
}

但是，这似乎仅在我在程序本身的窗口上方单击并拖动鼠标时才被调用.我尝试打电话给

But this seems to only be called when I click and drag the mouse while over the window of the program itself. I've tried calling

setMouseTracking(true);

在MainWindow的构造函数中，但这似乎没有什么不同(mouseMoveEvent仍然仅在我按住鼠标按钮时才调用，无论它在哪里).全局跟踪鼠标位置的最简单方法是什么?

in MainWindow's constructor, but this doesn't seem to do anything differently (mouseMoveEvent still is only called when I hold a mouse button down, regardless of where it is). What's the easiest way to track the mouse position globally?

推荐答案

您可以在应用程序上使用事件过滤器.

You can use an event filter on the application.

定义并实现布尔MainWindow :: eventFilter(QObject *，QEvent *).例如

Define and implement bool MainWindow::eventFilter(QObject*, QEvent*). For example

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
  if (event->type() == QEvent::MouseMove)
  {
    QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
    statusBar()->showMessage(QString("Mouse move (%1,%2)").arg(mouseEvent->pos().x()).arg(mouseEvent->pos().y()));
  }
  return false;
}

在构造MainWindows(或其他位置)时安装事件过滤器.例如

Install the event filter when the MainWindows is constructed (or somewhere else). For example

MainWindow::MainWindow(...)
{
  ...
  qApp->installEventFilter(this);
  ...
}

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