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QT多线程之---moveToThread用法
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在gui编程里，一个子函数的运行时间可能过长，界面就处于假死状态，原因是窗口是一个线程，子函数也在这个线程里，一些事件也要在这个线程里处理。
如果子函数运行时间过长，系统没有办法调用事件监听循环，gui就处于假死。一般有两种办法：
子函数事件不是很长，可以在子函数中间插入一些 QCoreApplication::processEvents
另一种方法就是把耗时的工作放到另一个线程里，通过信号槽来传递。这里介绍Qobject的moveToThread方法。
下面使用老板和员工的例子来讲，有两个BT老板，闲的蛋疼，安了个闹钟，每个一段时间查员工的岗。
代码如下：
#include <QCoreApplication>
#include <QThread>
#include <QTimer>
#include <QObject>
#include <QDebug>
#include "worker.h"
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
qDebug()<<"main thread is :"<<QThread::currentThreadId()<<endl; //打印主线程的线程号
QTimer *boss1 = new QTimer();
boss1->setInterval(5000);
QThread *t1=new QThread(); //来一个新的线程
t1->start(); //启动线程
Worker w1("Bob"); //创建一个对象
w1.moveToThread(t1); //把这个对象移到线程t1里
QObject::connect(boss1, SIGNAL(timeout()), &w1, SLOT(run())); //通过信号槽机制将boss1和worker1连接起来，每个一段时间查一次看看员工工作没 QTimer *boss2 =new QTimer();
boss2->setInterval(3000);
QThread *t2=new QThread(); //来一个新的线程
t2->start(); //启动线程
Worker w2("Stuart"); //创建一个对象
w2.moveToThread(t2); //把这个对象移到线程t2里
QObject::connect(boss2, SIGNAL(timeout()), &w2, SLOT(run())); boss1->start();
boss2->start(); return a.exec();
}
worker类
注意的是worker类一定要继承Qobject
#ifndef WORKER_H
#define WORKER_H#include <QObject>
#include <iostream>
class Worker : public QObject
{
Q_OBJECT
public:
explicit Worker(QString name, QObject *parent = nullptr);
long runnum=0;
QString name;signals:public slots:
void run(void);
};#endif // WORKER_H
#include "worker.h"
#include <QDebug>
#include <QThread>
Worker::Worker(QString name ,QObject *parent) : name(name),QObject(parent)
{
qDebug()<<"Hi, I'm worker:"<<name<<" at thread number:"<<QThread::currentThreadId()<<endl;
}void Worker::run()
{
runnum++;
qDebug()<<"I'm "<<name<<" don't spy me so frequently boss! I'm busy in my work..........";
qDebug()<<"you have spy me "<<runnum<<" times!"<< "I'm working at thread num :"<<QThread::currentThreadId()<<endl;
long s=1000;
for (long i=0; i<s;i++){ }}
运行后的结果：
main thread is : 0x6be0Hi, I'm worker: "Bob" at thread number: 0x6be0Hi, I'm worker: "Stuart" at thread number: 0x6be0I'm "Stuart" don't spy me so frequently boss! I'm busy in my work..........
you have spy me 1 times! I'm working at thread num : 0x36c0I'm "Bob" don't spy me so frequently boss! I'm busy in my work..........
you have spy me 1 times! I'm working at thread num : 0x5ff0I'm "Stuart" don't spy me so frequently boss! I'm busy in my work..........
you have spy me 2 times! I'm working at thread num : 0x36c0I'm "Stuart" don't spy me so frequently boss! I'm busy in my work..........
you have spy me 3 times! I'm working at thread num : 0x36c0I'm "Bob" don't spy me so frequently boss! I'm busy in my work..........
I'm "Stuart" don't spy me so frequently boss! I'm busy in my work..........
you have spy me 2 times! I'm working at thread num : 0x5ff0you have spy me 4 times! I'm working at thread num : 0x36c0I'm "Bob" don't spy me so frequently boss! I'm busy in my work..........
I'm "Stuart" don't spy me so frequently boss! I'm busy in my work..........
不知道你们又遇到BT的老板吗。
