Qt 多线程——继承于QThread类的使用方法

方法

自定义一个继承QThread的类Thread，重载QThread中的run()函数，在run()函数中写入需要执行的工作；
调用start()函数来启动线程，调用start函数时，会自动调用run函数。

运行效果

代码示例

thread.h文件

#ifndef THRAED1_H
#define THRAED1_H

#include <QThread>

class Thread : public QThread
{
    
    
    Q_OBJECT
public:
    explicit Thread(QObject *parent = nullptr);
    
    static Thread* GetInst()
    {
    
    
        static Thread hw;
        return &hw;
    }
    void reSetExit() {
    
     m_bIsExitThread = !m_bIsExitThread; }
    void reSetStop() {
    
     m_bIsStopThread = !m_bIsStopThread; }
signals:
    void sigValue(int value);

protected:
    void run() override;

private:
    bool m_bIsExitThread = true;  //退出线程
    bool m_bIsStopThread = false;  //暂停线程
    int fValue = 0;

};

#endif // THRAED1_H

thread.cpp文件

#include "thread.h"
#include<QDebug>
Thread::Thread(QObject *parent) : QThread(parent)
{
    
    

}

void Thread::run()
{
    
    
    fValue = 0;
    while(true)
    {
    
    
        if(isInterruptionRequested())
            break;
        if(m_bIsStopThread)
            continue;
        if(m_bIsExitThread)
            break;
        fValue++;
        emit sigValue(fValue);
        msleep(50);
    }

}

widget.h文件

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include "thread.h"

namespace Ui {
    
    
class Widget;
}

class Widget : public QWidget
{
    
    
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();

private slots:
    void on_btnStart_clicked();
    void on_btnStop_clicked();
    
private:
    Ui::Widget *ui;
    Thread *my_thread = nullptr;
};

#endif // WIDGET_H

widget.cpp文件

#include "widget.h"
#include "ui_widget.h"
#include<QDebug>
Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    
    
    ui->setupUi(this);

    my_thread = Thread::GetInst();
	//线程退出信号
    connect(my_thread, &Thread::finished, [&]{
    
    
        qDebug()<<"finished...";
        ui->textEdit->append("finished");

    });
    
	//线程int值变化信号
    connect(my_thread, &Thread::sigValue, this, [&](int value){
    
    
        QString str = QString(QStringLiteral("线程输出:%1")).arg(value);
        ui->textEdit->append(str);
    });
}

Widget::~Widget()
{
    
    
    //my_thread->quit();
    //退出线程
    my_thread->wait();
    delete ui;
}

void Widget::on_btnStart_clicked()
{
    
    
    if(my_thread->isRunning())
    {
    
    
        ui->btnStart->setText(QStringLiteral("启动"));
        my_thread->reSetExit();
    }
    else
    {
    
    
        ui->btnStart->setText(QStringLiteral("退出"));
        my_thread->reSetExit();
        my_thread->start();
    }
}

void Widget::on_btnStop_clicked()
{
    
    
    static bool bIsStop = true;
    my_thread->reSetStop();
    if(bIsStop)
    {
    
    
        ui->btnStop->setText(QStringLiteral("继续"));
        bIsStop = false;
    }
    else
    {
    
    
        ui->btnStop->setText(QStringLiteral("暂停"));
        bIsStop = true;
    }
}

Widget UI布局