c++ - QThread:线程仍在运行时被销毁了吗？

我想按按钮时启动QThread运行。但是编译器输出以下错误:

QThread: Destroyed while thread is still running
ASSERT failure in QThread::setTerminationEnabled(): "Current thread was not started with QThread.", file thread\qthread_win.cp.

我不知道我的代码有什么问题。

任何帮助，将不胜感激。

这是我的代码:

SamplingThread::SamplingThread( QObject *parent):
   QwtSamplingThread( parent ),
   d_frequency( 5.0 )
{
   init();
}

MainWindow::MainWindow( QWidget *parent ):
QMainWindow( parent )
{.......
  .....
   run= new QPushButton ("Run",this);
   stop= new QPushButton("Stop",this);
   connect(run, SIGNAL(clicked()),this, SLOT (start()));
}

MainWindow::start
{
   SamplingThread samplingThread;
   samplingThread.setFrequency( frequency() );
   samplingThread.start();
}

int main( int argc, char **argv )
{
   QApplication app( argc, argv );
   MainWindow window;
   window.resize( 700, 400 );
   window.show();
   bool ok = app.exec();
   return ok;
}

最佳答案

错误消息指出:QThread: Destroyed while thread is still running。您正在SamplingThread方法内创建MainWindow::start对象，但是当该方法终止时，它超出范围(即被销毁)。我看到两种简单的方法:

您将SamplingThread设为MainWindow的成员，因此其生存期与MainWindow实例

相同

您使用一个指针，即使用以下命令创建SamplingThreadSamplingThread *samplingThread = new SamplingThread;

这有帮助吗？

编辑:说明这两种情况，一个很粗糙的例子来说明这两种情况

#include <iostream>
#include <QApplication>
#include <QThread>

class Dummy
{
public:
  Dummy();
  void start();
private:
  QThread a;
};

Dummy::Dummy() :
  a()
{
}


void Dummy::start()
{
  a.start();
  QThread *b = new QThread;
  b->start();

  if( a.isRunning() ) {
    std::cout << "Thread a is running" << std::endl;
  }
  if( b->isRunning() ) {
    std::cout << "Thread b is running" << std::endl;
  }
}

int main(int argc, char** argv)
{
  QApplication app(argc,argv);
  Dummy d;
  d.start();
  return app.exec();
}