如何在Qt中覆盖QApplication :: notify [英] How to override QApplication::notify in Qt

问题描述

我试图在我的Qt应用程序中处理异常，我经历了几篇文章，指出了重写QApplication :: notify方法以有效地在Qt中处理异常。我不确定应该在哪里添加此重写的方法。是mainwindow.h还是main.cpp？我在MainWindow.h中添加了以下函数：

I am trying to handle exception in my Qt application, I went through a couple of posts which indicated of overriding the QApplication::notify method to handle exceptions in a efficient way in Qt. I am not sure where should I add this overriden method. Is it the mainwindow.h or main.cpp? I added the following function in my MainWindow.h:

bool
notify(QObject * rec, QEvent * ev)
{
  try
  {
    return QApplication::notify(rec,ev);
  }
  catch(Tango::DevFailed & e)
  {
    QMessageBox::warning(0,
                         "error",
                         "error");
  }

  return false;
}

在构建项目时，出现以下错误：

When I build my project I get the following error:

error: cannot call member function 'virtual bool QApplication::notify(QObject*, QEvent*)' without object

我是c ++和Qt的新手，能否让我知道如何实现这一点，以便有效处理所有异常方式，应用程序不会崩溃。

I am new to c++ and Qt.Could you let me know how I could implement this so that all my exceptions would be handled in an efficient way and the application does not crash.

推荐答案

这是QApplication对象的方法。为了重写notify方法，您必须从 QApplication 继承，并且在您的 main（）中，应将类实例化为Qt应用程序

This is a method of a QApplication object. In order to override the notify method you must inherit from QApplication and in your main() you should instantiate a class as the Qt Application

#include <QApplication>
class Application final : public QApplication {
public:
    Application(int& argc, char** argv) : QApplication(argc, argv) {}
    virtual bool notify(QObject *receiver, QEvent *e) override {
         // your code here
    }
};

int main(int argc, char* argv) {
    Application app(argc, argv);
    // Your initialization code
    return app.exec();
}

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