Introduce

There are two ways to implement thread according to official documentation and the first one is recommended

How to quit a thread correctly

Inherit QObject

workerThread.quit();
workerThread.wait();

Inherit QThread

Thread::Thread()
    : m_finishThread(false)
{
}

Thread::~Thread()
{
    m_finishThread = true;
    this->quit();
    this->wait();
}

Thread::run()
{
    while (!m_finishThread)
    {
        ...
    }
}

Be careful

• If you use the first solution, make sure worker class parent is nullptr otherwise it's still the main thread. You can use QThread::currentThreadId() to verify it. By the way, remember to connect QThread::finished() to delete the worker class since it doesn't have a parent

• In terms of the QThread class, please make sure the thread is not running after closing the application