继承 QThread
最后更新于：2022-04-02 02:13:06
[TOC]
## 概述
1. 继承 QThread 类重写了 run() 函数
2. 执行完成后发出一个完成信号
3. connect 处理 QThread::finished() 信号触发 QThread::deleteLater()
```
connect(thread, &WorkerThread::finished, thread, &WorkerThread::deleteLater);
```
4. 通过从run()函数直接或者间接地调用 QThread::exec(),可以让线程进入事件循环
```
while (true) {
//...code
exec();
}
```
## 示例
```
class WorkerThread : public QThread
{
Q_OBJECT
public:
WorkerThread(QObject *parent = 0)
: QThread(parent)
{
}
protected:
void run()
{
for (int i = 0; i < 1000000000; i++);
emit done();
}
signals:
void done();
};
// main.cpp
...
// 在GUI 中显示计时器
QTimer *timer = new QTimer(this);
connect(timer, &QTimer::timeout, [=]() {
static int sec = 0;
lcdNumber->display(QString::number(sec++));
});
WorkerThread *thread = new WorkerThread(this);
// 子线程处理完发出信号
connect(thread, &WorkerThread::done, timer, &QTimer::stop);
// 子线程完成后,删除子线程
connect(thread, &WorkerThread::finished, thread, &WorkerThread::deleteLater);
// 点击事件触发信号
connect(button, &QPushButton::clicked, [=]() {
timer->start(1);
thread->start();
});
```
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