Qt 中线程QThread的简单使用

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实验说明：将一个循环放到线程里运行，同时将信息显示在主界面上，使得主界面不卡。

1 main.cpp

#include <QtGui/QApplication>#include "dialog.h"int main(int argc, char *argv[]){    QApplication a(argc, argv);    Dialog w;    w.show();    return a.exec();}

2 dialog.h

#ifndef DIALOG_H#define DIALOG_H#include <QThread>#include <QtCore>#include <QtGui>#include"mythread.h"namespace Ui {    class Dialog;}class Dialog : public QDialog{    Q_OBJECTpublic:    explicit Dialog(QWidget *parent = 0);    ~Dialog();private slots:    void on_StartPthread_clicked();    void on_StopPthread_clicked();    void GetPthreadMessage(QString);private:    MyThread thread;    Ui::Dialog *ui;};#endif // DIALOG_H

3 dialog.cpp

#include "dialog.h"#include "ui_dialog.h"Dialog::Dialog(QWidget *parent) :    QDialog(parent),    ui(new Ui::Dialog){    ui->setupUi(this);    connect(&thread,SIGNAL(sendMessage(QString)),this,SLOT(GetPthreadMessage(QString)));    this->setFixedSize(300,100);}Dialog::~Dialog(){    delete ui;}void Dialog::GetPthreadMessage(QString recv){    ui->lineEdit->setText(recv);    qDebug()<<recv;}void Dialog::on_StartPthread_clicked(){    thread.start(); //就会调用 MyThread里的run函数    ui->StartPthread->setEnabled(false);    ui->StopPthread->setEnabled(true);}void Dialog::on_StopPthread_clicked(){   if(thread.isRunning())   {       thread.stop(); //就会调用 MyThread里的stop函数       ui->StartPthread->setEnabled(true);       ui->StopPthread->setEnabled(false);   }}

4 mythread.h

#ifndef MYTHREAD_H#define MYTHREAD_H#include <QThread>#include <QtGui>#include <QtCore>class MyThread : public QThread{    Q_OBJECTpublic:    explicit MyThread(QObject *parent = 0);    void run();    void stop();    bool stopped;    QString myString;   signals: void sendMessage(QString);//sendMessage为自定义信号public slots:};#endif // MYTHREAD_H

5 mythread.cpp

#include "mythread.h"MyThread::MyThread(QObject *parent) :    QThread(parent){    stopped=false;}void MyThread::run(){    qreal i=0;    while(!stopped)    {       qDebug()<<QString("in MyThread:%1").arg(i++);       myString=QString("in MyThread:%1").arg(i++);       emit sendMessage(myString);       this->msleep(100); //如果不用msleep等函数延时，主界面会卡住.    }    stopped=!stopped;}void MyThread::stop(){    stopped=true;}

6 效果图

线程开始

线程停止

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