如何在不同的 QT 线程中创建窗口?

2021-12-09 00:00:00 multithreading user-interface qt c++

我有一个应用程序，其中每个线程(主线程除外)都需要创建自己的窗口.我尝试创建一个线程，然后在 run 函数中调用 this->exec() .但是，我什至在调用之前收到一个错误:ASSERT 在 QWidget 中失败:Widgets must be created in the GUI thread."

I have an application in which each thread (except the main thread) needs to create its own window. I tried creating a thread and then calling this->exec() in the run function. However, I get an error before I even get to that call: ASSERT failure in QWidget: "Widgets must be created in the GUI thread."

我想弹出一个消息窗口.问题是源有多个线程，每个线程可能需要弹出自己的消息.

I want to popup a message window. The problem is that the source has multiple threads each of which may need to popup its own message.

推荐答案

如果你需要在不同的(非主)线程中创建 QWidget(或其他一些 gui 组件)，你可以在这样的线程中实现它方式:

If you need to create QWidget(or some other gui component(s)) in different(non-main) thread(s) you can implement it in such way:

  • 创建包含 gui 组件的简单包装器:

  • Create simple wrapper which holds gui component:

// gui component holder which will be moved to main thread
class gui_launcher : public QObject
{
  QWidget *w;
  // other components
  //..
public:
  virtual bool event( QEvent *ev )
  {   
    if( ev->type() == QEvent::User )
    {
      w = new QWidget;
      w->show();
      return true;
    }
    return false;
  }
};

  • 在主线程中创建QApplication对象

  • create QApplication object in main thread

    另一个线程主体:

    ..
  // create holder
  gui_launcher gl;
  // move it to main thread
  gl.moveToThread( QApplication::instance()->thread() );
  // send it event which will be posted from main thread
  QCoreApplication::postEvent( &gl, new QEvent( QEvent::User ) );
..

  • 开心点，:)

  • be happy, :)

    • 相关文章