声明一个处理函数;int timeTask();

头文件：

#include <QtConcurrent>
#include <QFuture>

并发处理改函数的任务，直到处理完成：

QFuture<int> ft = QtConcurrent::run(this, &ch72_concurrent::timeTask);while (!ft.isFinished()){QApplication::processEvents(QEventLoop::AllEvents, 30);}

带参数的函数：

将参数写在后面

QFuture<int> ft = QtConcurrent::run(this, &ch74::timeTask, num1, num2);

通过QFutureWatcher获取返回值：

QFutureWatcher<int>* fw = new QFutureWatcher<int>;connect(fw, &QFutureWatcher<int>::finished, [&]{qDebug() << "QFutureWatcher finished";qDebug() << "result = " << fw->result();});QFuture<int> ft = QtConcurrent::run(this, &ch74::timeTask, num1, num2);fw->setFuture(ft);while (!ft.isFinished()){QApplication::processEvents(QEventLoop::AllEvents, 30);}

完整代码

#include "ch74.h"
#include <QDebug>
#include <QtConcurrent>
#include <QFuture>
#include <QFutureWatcher>ch74::ch74(QWidget *parent): QWidget(parent)
{ui.setupUi(this);
}ch74::~ch74()
{}int ch74::timeTask(int& num1, int& num2)
{for (int i = 0; i < 1000; i++){num1++;num2++;qDebug() << num1;qDebug() << num2;}return num1 + num2;
}void ch74::on_pushButton_clicked()
{int num1 = 0;int num2 = 0;QFutureWatcher<int>* fw = new QFutureWatcher<int>;connect(fw, &QFutureWatcher<int>::finished, [&]{qDebug() << "QFutureWatcher finished";qDebug() << "result = " << fw->result();});QFuture<int> ft = QtConcurrent::run(this, &ch74::timeTask, num1, num2);fw->setFuture(ft);while (!ft.isFinished()){QApplication::processEvents(QEventLoop::AllEvents, 30);}
}