继承 QObject [推荐]
最后更新于：2022-04-02 02:13:03
[TOC]
## 概述
1. 利用继承QObject方法创建多线程，主要的步骤有一下几点：（注意：退出线程循环后，还要调用QThread::quit()函数，该线程才会触发`QThread::finished()`信号）
**流程**
1. 首先创建一个类MyThread，基类为QObject。
2. 在类MyThread中创建一个槽函数，用于运行多线程里面的代码。所有耗时代码，全部在这个槽函数里面运行。
3. 实例一个QThread线程对象（容器），将类MyThread的实例对象转到该容器中，用函数void QObject::moveToThread(QThread *thread);
```
myObjectThread->moveToThread(firstThread);
```
4. 用一个信号触发该多线程槽函数，比如用QThread::started()信号。
```
connect(firstThread,SIGNAL(started()),myObjectThread,SLOT(startThreadSlot()));
```
5. 用信号QThread::finished绑定槽函数QThread::deleteLatater()，在线程退出时，销毁该线程和相关资源。
```
connect(firstThread,SIGNAL(finished()),firstThread,SLOT(deleteLater()));
```
6. 所有线程初始化完成后，启动函数QThread::start()开启多线程，然后自动触发多线程启动信号QThread::started()。
## 示例
#include
class MyThread : public QObject {
public:
explicit MyThread(QObject *parent = nullptr);
void closeThread();
public slots:
void startThreadSLot();
private:
volatile bool isStop;
};
#endif
```
#include
class Widget : public QWidget
{
Q_OBJECT
public:
explicit Widget(QWidget *parent = nullptr);
void createView();
public slots:
void openThreads();
void closeThreads();
void finishedThread();
signals:
private:
MyThread* myThread;
QThread* thread;
QVBoxLayout *layout;
};
#endif // WIDGET_H
```
#include
Widget::Widget(QWidget *parent) : QWidget(parent)
{
createView();
thread = new QThread;
}
void Widget::createView()
{
qDebug()<<"启动进程";
layout=new QVBoxLayout(this);
QPushButton *openThreadBtn = new QPushButton(tr("打开线程"));
QPushButton *closeThreadBtn = new QPushButton(tr("关闭线程"));
layout->addWidget(openThreadBtn);
layout->addWidget(closeThreadBtn);
layout->addWidget(new QTextEdit());
layout->addStretch();
connect(openThreadBtn,&QPushButton::clicked,this,&Widget::openThreads);
connect(closeThreadBtn,&QPushButton::clicked,this,&Widget::closeThreads);
}
void Widget::openThreads()
{
qDebug()<isRunning()){
myThread->moveToThread(thread);
connect(thread,&QThread::finished,myThread,&MyThread::deleteLater);
connect(thread,&QThread::started,myThread,&MyThread::startThreadSLot);
thread->start();
qDebug()<<"QThread::currentThreadId() "<isRunning()){
myThread->closeThread();
myThread=nullptr;
thread->quit();
thread->wait();
}
}
void Widget::finishedThread()
{
qDebug()<<"多线程触发了";
}
```
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