发出Qt信号,但从未调用过时隙

问题描述 投票:0回答:1

我想使用插槽和信号连接两个对象(播放器和DownloadWebm),但是会发生一些奇怪的事情。这是我的代码:

  LogInWindow *log_in=new LogInWindow(cstr,centerX,centerY,start_byte,end_byte);
    QWidget::connect(log_in,SIGNAL(editingFinished()),&loop,SLOT(quit()));

    loop.exec();//stop executing bellow code till user input a movie id

    DownloadWebm *download_webm=nullptr;//download_webm is initialized in myThread constructor

    MyThread *DownloadWebm_Thread = new  MyThread(download_webm,cstr,start_byte,end_byte);

    DownloadWebm_Thread->start();//start the thread

    LinuxWebmPlayer *player = new LinuxWebmPlayer("video.webm",0);


    while(download_webm == nullptr){}//wait till download_webm is initialized

    qRegisterMetaType<Video_Bytes_Package>("Video_Bytes_Package");
    qRegisterMetaType<Info>("Info");

    QObject::connect(download_webm,SIGNAL(send_video_info(Info)),player,SLOT(set_video_info(Info)));
    QObject::connect(download_webm,SIGNAL(send_packege(Video_Bytes_Package)),player,SLOT(add_packeges(Video_Bytes_Package)));
    QObject::connect(download_webm,SIGNAL(send_finish_downloading(bool)),player,SLOT(video_is_commplet()));
    QObject::connect(download_webm,SIGNAL(send_one_cluster_recived()),player,SLOT(calculate_frames()));

  const bool connected =  QObject::connect(player,SIGNAL(yes()),download_webm,SLOT(slot()));
  emit player->yes();
  qDebug() << "Connection established?" << connected;//return true
  Q_ASSERT(connected);

[当我将download_webm连接到播放器时,插槽会接收从download_webm发出的信号但是,当我尝试将播放器连接到download_webm时,连接成功,但会发出信号,但永远不会调用来自download_webm的插槽。

  • DownloadWebm在另一个线程中运行。

这是我在downloadwebm中的信号声明:

 class DownloadWebm : public QObject
{

    Q_OBJECT

public:
    DownloadWebm();
    DownloadWebm(char *link,const char *app_path,long x,long y);
    void start();
public slots:
    void slot();
    void first_package_analyzed(int,long);

 private:
  ................
  ................ 

  signals:
   void send_packege(Video_Bytes_Package package);
   void send_video_info(Info info);
   void send_finish_downloading(bool) ;

和播放器标题:

   class LinuxWebmPlayer : public QMainWindow
{
    Q_OBJECT
public:

 LinuxWebmPlayer(char* argv,int pos);

signals:
    void send_cluster_size_frames(long);
    void yes();


public slots:
   void add_packeges(Video_Bytes_Package);
   void set_video_info(Info);
c++ qt signals-slots
1个回答
0
投票

我发现了问题,我的DownloadWebm对象中没有事件循环,因此当信号发出时,该对象已完成执行。

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