QT中创建和启动线程

短命女 2022-12-27 07:35 221阅读 0赞

## QT的线程，是通过信号和槽驱动的！！！ ##

首先，创建一个MyRun类，类里有一个可以使得线程运行的函数，比如说run方法。

**myrun.h：**

#ifndef MYRUN_H
    #define MYRUN_H
    
    #include <QObject>
    #include <QThread>
    #include <QDebug>
    class MyRun : public QObject
    {
        Q_OBJECT
    public:
        explicit MyRun(QObject *parent = nullptr);
    
        void run();
    
        void setStop(bool isStop = true);
    
    signals:
        void withSignal();
    
    private:
        bool isStop = false;
    
    };
    
    #endif // MYRUN_H

**myrun.cpp：**

#include "myrun.h"
    
    MyRun::MyRun(QObject *parent) : QObject(parent)
    {
    
    }
    
    
    void MyRun::run(){
        while(!isStop){
            QThread::msleep(1000);
            emit withSignal();
            qDebug() << QThread::currentThread();
        }
    }
    
    void MyRun::setStop(bool isStop){
        this->isStop = isStop;
    }

**widget.h：**

#ifndef WIDGET_H
    #define WIDGET_H
    
    #include <QWidget>
    #include "myrun.h"
    QT_BEGIN_NAMESPACE
    namespace Ui { class Widget; }
    QT_END_NAMESPACE
    
    class Widget : public QWidget
    {
        Q_OBJECT
    
    public:
        Widget(QWidget *parent = nullptr);
        ~Widget();
    
    
    private:
        Ui::Widget *ui;
    
        QThread * thread;
        MyRun * myRun;
    
        int num = 0;
    
    signals:
        void startThread();
    private slots:
        void on_startButton_clicked();
        void on_stopButton_clicked();
    };
    #endif // WIDGET_H

**widget.cpp：**

#include "widget.h"
    #include "ui_widget.h"
    
    Widget::Widget(QWidget *parent)
        : QWidget(parent)
        , ui(new Ui::Widget)
    {
        ui->setupUi(this);
    
        setWindowTitle("线程控制LCD");
    
        thread = new QThread(this);
    
        myRun = new MyRun();
    
        //将线程函数加入到线程里
        myRun->moveToThread(thread);
    
        this->connect(myRun,&MyRun::withSignal,[=](){
            ui->lcdNumber->display(num ++);
        });
    
        this->connect(this,&Widget::startThread,myRun,&MyRun::run);
    
        //按右上角关闭按钮的信号与槽的连接
        this->connect(this,&Widget::destroyed,[=](){
            myRun->setStop(true);
            thread->quit();
            thread->wait();
            delete myRun;
        });
    }
    
    Widget::~Widget()
    {
        delete ui;
    }
    
    
    void Widget::on_startButton_clicked()
    {
        thread->start();
        myRun->setStop(false);
        emit startThread();
    }
    
    void Widget::on_stopButton_clicked()
    {
        myRun->setStop(true);
        thread->quit();
        thread->wait();
    }

### 另一个例子： ###

**myRun.cpp：**

#include "myrun.h"
    
    MyRun::MyRun(QObject *parent) : QObject(parent)
    {
    
    }
    
    void MyRun::run()
    {
        while(isRunning){
            QThread::msleep(1000);
    
            qDebug() << QUuid::createUuid().toString();
        }
    }
    
    void MyRun::setRunning(bool isRunning)
    {
        this->isRunning = isRunning;
    }

**widget.cpp：**

#include "widget.h"
    
    Widget::Widget(QWidget *parent)
        : QWidget(parent)
    {
        MyRun * myRun = new MyRun();
        QThread * thread = new QThread(this);
        myRun->moveToThread(thread);
    
    
        this->connect(thread,&QThread::started,myRun,&MyRun::run);
    
        thread->start();
    
        this->connect(this,&Widget::destroyed,[=](){
            myRun->setRunning(false);
            thread->quit();
            thread->wait();
            delete myRun;
        });
    }
    
    Widget::~Widget()
    {
    }