QT使用QThread启动线程的方法 

 创建项目文件基类选择QDialog,添加两个按钮

分别按钮右键-》转到槽，添加代码

点击启动线程，

thread2.start();默认调用my_thread类的run函数

#include "dialog.h"
#include "ui_dialog.h"
#include 
 
 
Dialog::Dialog(QWidget *parent)
    : QDialog(parent)
    , ui(new Ui::Dialog)
{
    ui->setupUi(this);
}
 
Dialog::~Dialog()
{
    delete ui;
}
 
 
void Dialog::on_pushButton_start_clicked()
{
    thread2.start();
    ui->pushButton_start->setEnabled(false);
    ui->pushButton_stop->setEnabled(true);
}
 
void Dialog::on_pushButton_stop_clicked()
{
    if(thread2.isRunning())
    {
        thread2.stop();
        ui->pushButton_start->setEnabled(true);
        ui->pushButton_stop->setEnabled(false);
    }
    else
    {
        qDebug()<<tr("线程已经停止");
    }
}

dialog.h

#ifndef DIALOG_H
#define DIALOG_H
 
#include 
#include "my_thread.h"
 
QT_BEGIN_NAMESPACE
namespace Ui { class Dialog; }
QT_END_NAMESPACE
 
class Dialog : public QDialog
{
    Q_OBJECT
 
public:
    Dialog(QWidget *parent = nullptr);
    ~Dialog();
 
private slots:
    void on_pushButton_start_clicked();
 
    void on_pushButton_stop_clicked();
 
private:
    Ui::Dialog *ui;
    my_thread thread2;
};
#endif // DIALOG_H

 

#include 

创建my_thread的类

头文件：

#ifndef MY_THREAD_H
#define MY_THREAD_H
#include 
 
 
class my_thread : public QThread
{
    Q_OBJECT
public:
    explicit my_thread(QObject *parent = 0);
    void stop();
protected:
    void run();
private:
    volatile bool stopped;//volatile可以使stopped变量任何时候都保持最新的值
};
 
#endif // MY_THREAD_H

cpp文件

 

#include "my_thread.h"
#include 
 
my_thread::my_thread(QObject * parent):QThread(parent)
{
   stopped=false;
}
void my_thread::run()
{
    qreal i=0;// QT的浮点型
    while(!stopped)
    {
        qDebug()<<QString("in my_thread:%1").arg(i);
        msleep(1000);
        i++;
    }
    stopped = false;
    qDebug()<<tr("线程已经停止啦");
}
void my_thread::stop()
{
    stopped=true;
}