QT学习之旅 - QThread多线程

其实QT中的thread(线程)是很容易的

首先是主线程

#include "mainwindow.h"
#include "ui_mainwindow.h"#include <QDebug>MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);//threadTest = new ThreadTest;//线程实例//threadTest->start();//开启线程for(int i=0;i<100;i++){qDebug() << "mainwindow i:" << i;_sleep(500);}}MainWindow::~MainWindow()
{delete ui;
}

其次是一个程序

#include "test.h"
#include <QDebug>Test::Test()
{for(int i=0;i<100;i++){qDebug() << "i=" << i;_sleep(1000);}
}Test::~Test(){}

通过一个QThread来放入程序

#include "threadtest.h"
#include <QDebug>ThreadTest::ThreadTest()
{}void ThreadTest::run(){test = new Test;
}
void ThreadTest::stop(){}ThreadTest::~ThreadTest(){}

一个简单的线程就实现了

进阶一点: 手动开启关闭线程

添加一个按键，通过信号和槽来控制线程使能关闭

#include "mainwindow.h"
#include "ui_mainwindow.h"#include <QDebug>
#include <QPushButton>bool isTrue;MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);isTrue = true;threadTest = new ThreadTest;connect(ui->pushButton,&QPushButton::clicked,this,&MainWindow::on_button_test);for(int i=0;i<100;i++){qDebug() << "mainwindow i:" << i;_sleep(100);}}void MainWindow::on_button_test(){if(isTrue){threadTest->start();isTrue = false;ui->pushButton->setText("关闭线程");}else{threadTest->stop();isTrue = true;ui->pushButton->setText("开启线程");}
}MainWindow::~MainWindow()
{delete ui;
//    threadTest->de;delete threadTest;
}

#include "threadtest.h"
#include <QDebug>ThreadTest::ThreadTest()
{}void ThreadTest::run(){test = new Test;
}
void ThreadTest::stop(){this->quit();this->wait();
}ThreadTest::~ThreadTest(){}

Test不变。现象是mainwindow i:99(执行完)后窗口出现，之后开启线程。开启后立马关闭，会执行到i=99(线程执行完)后才关闭

俩个线程

继第一个线程后，我们再来一个线程，也是在主函数中实例。查看情况

#include "threadtesttwo.h"
#include <QDebug>ThreadTestTwo::ThreadTestTwo()
{}
void ThreadTestTwo::run(){for(int i=0;i<100;i++){qDebug() << "threadTwo i=" << i;_sleep(200);}
}
void ThreadTestTwo::stop(){}
ThreadTestTwo::~ThreadTestTwo(){}

#include "mainwindow.h"
#include "ui_mainwindow.h"#include <QDebug>
#include <QPushButton>bool isTrue;MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);isTrue = true;threadTest = new ThreadTest;threadTestTwo = new ThreadTestTwo;connect(ui->pushButton,&QPushButton::clicked,this,&MainWindow::on_button_test);}void MainWindow::on_button_test(){if(isTrue){threadTest->start();threadTestTwo->start();isTrue = false;ui->pushButton->setText("关闭线程");}else{threadTest->stop();threadTestTwo->stop();isTrue = true;ui->pushButton->setText("开启线程");}
}MainWindow::~MainWindow()
{delete ui;delete threadTest;
}