mythread.h文件

#ifndef MYTHREAD_H
#define MYTHREAD_H
#include

class myThread : public QObject
{
Q_OBJECT
public:
explicit myThread(QObject *parent = );
//线程处理函数
void myTimeout();

void setFlag(bool flag = true);

signals:
void mySignal();

public slots:

private:
bool isStop;
};

#endif // MYTHREAD_H

mythread.cpp文件

#include "mythread.h"
#include
#include

myThread::myThread(QObject *parent) : QObject(parent)
{
isStop = false;
}

void myThread::myTimeout()
{
while( !isStop )
{

 QThread::sleep();  
 emit mySignal();

  qDebug() << "子线程号：" << QThread::currentThread();

  if(isStop)  
  {  
      break;  
  }  

}
}

void myThread::setFlag(bool flag)
{
isStop = flag;
}

widget.h文件

#ifndef WIDGET_H
#define WIDGET_H
#include "mythread.h"
#include
#include
#include
#include
namespace Ui {
class Widget;
}

class Widget : public QWidget
{
Q_OBJECT

public:
explicit Widget(QWidget *parent = );
~Widget();
void dealSignal();
void dealClose();

signals:
void startThread(); //启动子线程的信号

private slots:

void on_start_clicked();

void on_stop_clicked();

private:
Ui::Widget *ui;
myThread *myT;
QThread *thread;
};

#endif // WIDGET_H

widget.cpp文件

#include "widget.h"
#include "ui_widget.h"
#include "mythread.h"
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
myT = new myThread;//不能初始化指定父类myThread(this)

//创建子线程
thread = new QThread(this);

//把自定义线程加入到子线程中
myT->moveToThread(thread);

connect(myT, &myThread::mySignal, this, &Widget::dealSignal);

qDebug() << "主线程号：" << QThread::currentThread();

connect(this, &Widget::startThread, myT, &myThread::myTimeout);

//窗口关闭时调用线程关闭，前提是线程要运行完当前任务
connect(this, &Widget::destroyed, this, &Widget::dealClose);

}

Widget::~Widget()
{
delete ui;
}

void Widget::dealClose()
{
on_stop_clicked();
delete myT;
}

void Widget::dealSignal()
{
static int i = ;
i++;
ui->lcdNumber->display(i);
}

void Widget::on_start_clicked()
{
if(thread->isRunning() == true)
{
return;
}

//启动线程，但是没有启动线程处理函数
thread->start();
myT->setFlag(false);

//不能直接调用线程处理函数，
//直接调用，导致，线程处理函数和主线程是在同一个线程
//只能通过 signal - slot 方式调用
emit startThread();
}

void Widget::on_stop_clicked()
{
if(thread->isRunning() == false)
{
return;
}

myT->setFlag(true);
thread->quit();
thread->wait();
}