C++ Qt Gui线程存在阻塞问题

我是初级程序员

最近，我使用Halcon库实现了图像抓取

当我按下live按钮时，计时器开始抓取图像。它工作，但主屏幕冻结到计时器周期

所以，我正在改进使用线程的图像抓取性能

首先，我实现了如下线程

    m_pThread = new QThread();
    m_pUpdateWorker = new ImageUpdateWorker(nullptr, strName);
    m_pUpdateWorker->moveToThread(m_pThread); // UpdateWorker move to Thread

    connect(m_pThread, SIGNAL(started()), m_pUpdateWorker, SLOT(run()));
    connect(m_pThread, SIGNAL(finished()), m_pThread, SLOT(deleteLater()));
    connect(m_pUpdateWorker, SIGNAL(finished()), m_pThread, SLOT(quit()));
    connect(m_pUpdateWorker, SIGNAL(finished()), m_pUpdateWorker, SLOT(deleteLater()));
    connect(m_pUpdateWorker, SIGNAL(grab()), this, SLOT(onGrab()));

[ImageUpdateWorker.h]

class ImageUpdateWorker : public QObject
{
    Q_OBJECT

public:
    explicit ImageUpdateWorker(QObject* parent = 0, QString strThreadName = "ImageUpdateWorker");
    ~ImageUpdateWorker();

signals:
    void finished();
    void grab();

public slots:
    void run();

private:
    bool m_bStop{ false };
};

[ImageUpdateWorker.cpp]

ImageUpdateWorker::ImageUpdateWorker(QObject* parent, QString strThreadName)
    : QObject(parent)
{
    setObjectName(strThreadName);
}

ImageUpdateWorker::~ImageUpdateWorker()
{
}

void ImageUpdateWorker::run()
{
    while (m_bStop == false)
    {
        emit grab();
    }

    emit finished();
}

第二，我实现了继承的QWidget UI小部件，输出屏幕如下

    m_pThread = new QThread();
    m_pUpdateWorker = new ImageUpdateWorker(nullptr, strName);
    m_pUpdateWorker->moveToThread(m_pThread); // UpdateWorker move to Thread

    connect(m_pThread, SIGNAL(started()), m_pUpdateWorker, SLOT(run()));
    connect(m_pThread, SIGNAL(finished()), m_pThread, SLOT(deleteLater()));
    connect(m_pUpdateWorker, SIGNAL(finished()), m_pThread, SLOT(quit()));
    connect(m_pUpdateWorker, SIGNAL(finished()), m_pUpdateWorker, SLOT(deleteLater()));
    connect(m_pUpdateWorker, SIGNAL(grab()), this, SLOT(onGrab()));

当我调用“m_pThread->start（）；”时，屏幕开始出现阻塞：(

如果您有任何建议或信息，我将不胜感激。谢谢您的阅读。

我在QT中不知道。 我把我在C#中使用的代码发给你了

如果不想冻结GUI，则必须使用委托

hdisplay是对象HalconDotNet:HWindowControlWPF

camera是我定义相机参数的类

摄像头内。抓取有代码：

  HOperatorSet.GrabImage(out ho_Image, _AcqHandle);
  h_Image = new HImage(ho_Image);

    // Initialise the delegate 
    updateLiveDelegate = new UpdateLiveDelegate(this.UpdateLive);

    HImage ho_Image = new HImage();

初始化时有以下代码：

  HOperatorSet.GrabImage(out ho_Image, _AcqHandle);
  h_Image = new HImage(ho_Image);

    // Initialise the delegate 
    updateLiveDelegate = new UpdateLiveDelegate(this.UpdateLive);

    HImage ho_Image = new HImage();

下面是我使用的代码：

    // ==================
    // LIVE
    // ==================

    bool stopLive = true;

    // Declare the thread
    private Thread liveThread = null;

    // Declare a delegate used to communicate with the UI thread
    private delegate void UpdateLiveDelegate();
    private UpdateLiveDelegate updateLiveDelegate = null;


    private void btnLive_Click(object sender, RoutedEventArgs e)
    {

        try
        {
            stopLive = !stopLive;

            // if stopLive = false, live camera is activated
            if (!stopLive)
            {

                // Launch the thread
                liveThread = new Thread(new ThreadStart(Live));
                liveThread.Start();
            }


        }
        catch (Exception ex)
        {
            // Error

        }

    }


    private void Live()
    {

        try
        {

            while (stopLive == false)
            {

                if (camera.Grab(out ho_Image))
                {
                    // Show progress
                    Dispatcher.Invoke(this.updateLiveDelegate);
                }
                else
                {
                    // No grab
                    stopLive = true;

                }
            }

            // here stopLive is true


        }
        catch (Exception ex)
        {
            // Error
        }




    }

    private void UpdateLive()
    {

        try
        {
            int imageHeight;
            int imageWidth;
            string imageType;
            ho_Image.GetImagePointer1(out imageType, out imageWidth, out imageHeight);

            hDisplay.HalconWindow.SetPart(0, 0, imageHeight - 1, imageWidth - 1);

            // display
            hDisplay.HalconWindow.DispImage(ho_Image);
        }
        catch (Exception ex)
        {
            // Error
        }


    }

---

使用m_pImageUpdateThread->moveToThread（m_pThread）

调用

process

时，

grab

发出多少次？我不知道确切的计数。有一件事是grab发出这么多次。@JarManRight，我不需要确切的数字。但这几乎肯定会导致在循环中发出信号的方式出现问题。为什么它需要发出这么多次呢频繁地？当我添加sleep in而循环冻结没有修复时。我不知道为什么抓取被冻结。如何调用

进程

？void ImageUpdateWorker:：run（）在循环中发出信号，只是溢出事件队列（使用排队连接）。添加一些sleep（）或仅在接收到下一帧抓取后才发出抓取。