QThread之moveToThread用法

简介

使用moveToThread函数的流程如下：
1、创建一个类继承自QObject类或其子类，并在其中定义所要执行的多个任务，执行多个任务就要定义相应的信号。
2、任务通过moveToThread指定所要执行的线程。
3、线程通过start启动
4、通过信号与槽机制触发线程的执行

为什么要用

适用场景：

适合单次任务执行，即有点像懒人，触发一下，干一次活
适合干完活，需要主动推送一个通知
适合用于简化多线程中，对数据安全的保护

它不适用的场景:

不适用高频率任务，即跑完一个任务，可能没有时间休息，持续跑
执行高频率任务，还是需要使用重写QThread::run()的方式，来实现

示例一个循环读取进度条的模型
在这里插入图片描述

1.首先定义我们的worker
头文件

//
// Created by zhe.xiao on 2023/12/05.
//

#pragma once

#include "std_include.h"
#include <QObject>


class OperationWorker : public QObject
{
Q_OBJECT
public:
    explicit OperationWorker(QObject* parent = nullptr);
    ~OperationWorker();

signals:
    void SendRecordImportProgress(QString ecgPath);

public slots:
    void ProcessRecordImportProgress(QString ecgPath);
};

cpp文件

//
// Created by zhe.xiao on 2023/12/05.
//

#include "operation_worker.h"
#include <QThread>

OperationWorker::OperationWorker(QObject* parent) : QObject(parent)
{

}

OperationWorker::~OperationWorker()
{

}

void OperationWorker::ProcessRecordImportProgress(QString ecgPath)
{
    qDebug("===OperationWorker ProcessRecordImportProgress, ecgPath=%s", ecgPath.toStdString().c_str());

    int i = 0;
    while (i <= 100)
    {
        std::string percent = std::to_string(i) + "%";
        emit SendRecordImportProgress(QString(percent.c_str()));
        i += 15;
    }
}

2.定义一个控制器，专门来控制worker

头文件
//
// Created by zhe.xiao on 2023/12/05.
//

#pragma once

#include "std_include.h"
#include "operation_worker.h"
#include <QObject>
#include <QThread>

class OperationController : public QObject
{
Q_OBJECT
public:
    explicit OperationController(QObject* parent = nullptr);

    ~OperationController() override;

    //触发读取记录仪进度条
    void StartRecordImportProgress();

signals:
    void TriggerRecordImportProgress(QString ecgPath);

public slots:
    void ReceiveRecordImportProgress(QString percent);

private:
    QThread m_workThread;
};

cpp文件

//
// Created by zhe.xiao on 2023/12/05.
//

#include "operation_controller.h"

OperationController::OperationController(QObject* parent) : QObject(parent)
{
    auto operationWorker = new OperationWorker();
    operationWorker->moveToThread(&m_workThread);

    //绑定事件
    connect(&m_workThread, &QThread::finished, operationWorker, &QObject::deleteLater);
    connect(this, &OperationController::TriggerRecordImportProgress, operationWorker, &OperationWorker::ProcessRecordImportProgress);
    connect(operationWorker, &OperationWorker::SendRecordImportProgress, this, &OperationController::ReceiveRecordImportProgress);

    //线程启动
    m_workThread.start();
}

OperationController::~OperationController()
{
    m_workThread.quit();
    m_workThread.wait();
}

void OperationController::StartRecordImportProgress()
{
    emit TriggerRecordImportProgress("xiaozhe");
}

void OperationController::ReceiveRecordImportProgress(QString percent)
{
    qDebug("===OperationController ReceiveRecordImportProgress, percent=%s", percent.toStdString().c_str());
}

注：由于Worker是QObject对象，同时通过connect(&thread, &QThread::finished, operationWorker, &QObject::deleteLater)建立信号槽；当线程释放时，会自动删除Worker对象，并不会内存泄漏。

3.外部函数触发执行

int OperationRecorderImport::Test()
{
    auto operationController = new OperationController();;
    operationController->StartRecordImportProgress();

    return OPERATION_SUCCESS;
}