Qt测试代码执行时间

 //////////////////////////////////////////////////////////////////
         QString _GetIntervalTime(QTime& time, QString strInfo)
         {
             int ntime_Diff = time.elapsed();//返回从上次start()或restart()开始以来的时间差，单位ms
             //以下方法是将ms转为s
             float f = ntime_Diff/1000.0;
             QString tr_timeDiff = QString("%1").arg(f); //float->QString
             return strInfo + ": " + tr_timeDiff;
         }

         void _WriteFile(QString str)
         {
             QString strFileName = "E:/debug.txt";
             QFile::remove(strFileName);
             QFile myfile(strFileName);
             myfile.open(QIODevice::WriteOnly);
             myfile.write(str.toLatin1());
             myfile.close();
         }
         //---------------------------------------------------------------------------------------
         void A::excuteSimulation()
         {
             TfSimulation mTfSim(mRenderView);

             QTime time;//开始计时
             QString strInfo;
             time.start();

             strInfo += _GetIntervalTime(time, QString::fromLocal8Bit("simPanel: ")) + ("\r\n");
             strInfo += _GetIntervalTime(timeTotal, QString::fromLocal8Bit("TotalTime: ")) + ("\r\n");
             _WriteFile(strInfo);
         }