Qt的信号槽机制可以将任何继承自QObject类的对象捆绑在一起，使不同对象之间能相互通信。QThread继承自QObject，能够发射信号和定义槽函数

• thread.h

#ifndef THREAD_H
#define THREAD_H
#include <QThread>
#include <QString>class Thread : public QThread
{Q_OBJECT
public:Thread(QObject *parent);virtual void run();signals:void send(QString msg);
private:
};#endif

• thread.cpp

#include "thread.h"
#include <QDebug>Thread::Thread(QObject *parent) :QThread(parent)
{}
void Thread::run()
{msleep(100);//发送一个信号给主线程qDebug()<<"Thread id :" <<this->currentThreadId() << "is running";emit send(QString("thread"));
}

• widget.h

#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>
#include <QPainter>
#include "thread.h"namespace Ui {
class Widget;
}class Widget : public QWidget
{Q_OBJECT
public:explicit Widget(QWidget *parent = nullptr);~Widget();public slots:void accept(QString msg);private slots:void on_pushButton_clicked();private:Ui::Widget *ui;
};
#endif // WIDGET_H

• widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include "thread.h"
#include <qdebug.h>
#include <QDebug>Widget::Widget(QWidget *parent) :QWidget(parent),ui(new Ui::Widget)
{ui->setupUi(this);t = new Thread(NULL);connect(t, SIGNAL(send(QString)), this, SLOT(accept(QString)),Qt::QueuedConnection);
}Widget::~Widget()
{t->wait();delete ui;
}void Widget::accept(QString msg)
{qDebug()<<tr("完成信号触发");
}
void Widget::on_pushButton_clicked()
{t->start();
}