上面例子没看到processEvent的使用-QT开发中文网

非常抱歉，是我疏忽了。在上面的例子中确实没有使用QCoreApplication::processEvents()。以下是一个更新后的示例，演示如何在等待worker线程完成之前处理GUI事件：

#include <QtWidgets>
#include <QtCore>

class Worker : public QObject
{
    Q_OBJECT
public:
    explicit Worker(QObject *parent = nullptr) : QObject(parent) {}

signals:
    void resultReady(const QString &result);

public slots:
    void doWork()
    {
        // Do some heavy work here...
        QThread::sleep(3);
        QString result = "Hello World from worker thread!";
        emit resultReady(result);
    }
};

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    explicit MainWindow(QWidget *parent = nullptr) : QMainWindow(parent)
    {
        setCentralWidget(new QLabel("Click the button to start processing..."));
        QPushButton *button = new QPushButton("Start Processing", this);
        connect(button, &QPushButton::clicked, this, &MainWindow::startProcessing);
    }

private slots:
    void startProcessing()
    {
        // Disable UI controls and show progress bar.
        centralWidget()->setEnabled(false);
        m_progressBar = new QProgressBar(this);
        statusBar()->addWidget(m_progressBar);

        // Create worker object and move it to a separate thread.
        m_workerThread = new QThread(this);
        Worker *worker = new Worker();

        connect(worker, &Worker::resultReady, this, &MainWindow::handleResult);

         // Move worker to a separate thread and start it.
         worker->moveToThread(m_workerThread);
         connect(m_workerThread, &QThread::started, worker, &Worker::doWork);
         connect(worker, &Worker::resultReady, m_workerThread, &QThread::quit);

         // Wait for the worker thread to finish before cleaning up.
         connect(m_workerThread, &QThread::finished, [this]() {
             m_workerThread->deleteLater();
             m_progressBar->deleteLater();
             centralWidget()->setEnabled(true);
         });

         // Start the worker thread and show progress bar.
         m_progressBar->setRange(0, 0);
         m_workerThread->start();

         // Process events until the worker thread finishes.
         while (m_workerThread->isRunning()) {
            qApp->processEvents();
            QCoreApplication::sendPostedEvents(nullptr, QEvent::DeferredDelete);
         }
    }

    void handleResult(const QString &result)
    {
        // Update UI with the result from worker thread.
        QLabel *label = new QLabel(result, this);
        setCentralWidget(label);
    }

private:
    QThread *m_workerThread;
    QProgressBar *m_progressBar;
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow window;
    window.show();
    return app.exec();
}

#include "main.moc"

在上面的示例中，我们将QCoreApplication::processEvents()函数添加到了启动worker线程之后的循环中。这将确保事件循环能够响应GUI事件，并且在等待worker线程完成时不会阻塞。

注意，我们还使用了QCoreApplication::sendPostedEvents()函数来删除所有延迟删除事件，以避免资源泄漏。