第一步：

pro引入

QT       += network

第二步：

.h

#include <QtNetwork/QNetworkRequest>
#include <QtNetwork/QNetworkAccessManager>
    Q_OBJECT // 使用槽，訊號必須要加入此巨集
signals:
    void m_request_fail(int code,QString msg);
public:
    QByteArray sendPostRequest(QNetworkRequest request,QByteArray sendData);
    QByteArray sendGetRequest(QNetworkRequest request);
 
protected:
// 成員變數 
    QNetworkAccessManager *m_pHttpMgr; 
    QTimer* m_requestTimeoutTimer;

.cpp

// 構造方法初始化
    m_pHttpMgr = new QNetworkAccessManager(this);
    qDebug() << "m_pHttpMgr:" << m_pHttpMgr->supportedSchemes();
    m_requestTimeoutTimer = new QTimer(m_pHttpMgr);
    m_requestTimeoutTimer
 
->setSingleShot(true);// 單次觸發
    m_requestTimeoutTimer->setInterval(1000);

/**
 用法
//設定url
QString url = "http://10.0.0.20:8005/order/charge";
//設定頭資訊
QNetworkRequest requestInfo;
requestInfo.setUrl(QUrl(url));
requestInfo.setHeader(QNetworkRequest::ContentTypeHeader,QVariant("application/json"));
requestInfo.setRawHeader("Content-Type","application/json");//伺服器要求的資料頭部
//傳送資料
QByteArray qByteHttpData = sendJson();
MyThread::sendPostRequest->sendPostRequest(requestInfo, qByteHttpData);
 * @brief MyThread::sendPostRequest
 * @param request
 * @param sendData
 * @return
 
 
*/
QByteArray MyThread::sendPostRequest(QNetworkRequest request,QByteArray sendData){
    QNetworkReply *reply =  m_pHttpMgr->post(request, sendData);
    //新增事件迴圈機制，返回後再執行後面的
    QEventLoop eventLoop;
    connect(m_requestTimeoutTimer,&QTimer::timeout,&eventLoop,&QEventLoop::quit);
    connect(reply, &QNetworkReply::finished, &eventLoop, &QEventLoop::quit);
    m_requestTimeoutTimer->start();
    eventLoop.exec();       //block until finish
    if(m_requestTimeoutTimer->isActive()){
        m_requestTimeoutTimer->stop();
        //錯誤處理
        if (reply->error() == QNetworkReply::NoError)
        {
            qDebug() << "request protobufHttp NoError";
        }
        else
        {
            qDebug()<<"request protobufHttp handle errors here";
            QVariant statusCodeV = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
            //statusCodeV是HTTP伺服器的相應碼，reply->error()是Qt定義的錯誤碼，可以參考QT的文件
            qDebug() << "request protobufHttp found error ....code: %d %d\n" << statusCodeV.toInt() << (int)reply->error();
            qDebug() << "request error fail:" << reply->errorString();
            emit m_request_fail(statusCodeV.toInt(),reply->errorString());
        }
    }else{
        disconnect(m_requestTimeoutTimer,&QTimer::timeout,&eventLoop,&QEventLoop::quit);
        emit m_request_fail(-1,"timeout");
    }
    //請求收到的結果
    QByteArray response = reply->readAll();
    reply->abort(); reply->deleteLater();
    return response;
}
/**
  用法
    //設定url
    QString url = "http://10.0.0.20:8005/vending_machine/items/ac83f39ea268";//fae4b325e52c
    QNetworkRequest requestInfo;
    requestInfo.setUrl(QUrl(url));
    myThread->sendGetRequest(requestInfo);
 * @brief MyThread::sendGetRequest
 * @param request
 * @return
 */
QByteArray MyThread::sendGetRequest(QNetworkRequest request){
    //新增事件迴圈機制，返回後再執行後面的
    QEventLoop eventLoop;
    QNetworkReply *reply =  m_pHttpMgr->get(request);
    connect(m_requestTimeoutTimer,&QTimer::timeout,&eventLoop,&QEventLoop::quit);
    connect(reply, SIGNAL(finished()), &eventLoop, SLOT(quit()));
    m_requestTimeoutTimer->start();
    eventLoop.exec();       //block until finish
    if(m_requestTimeoutTimer->isActive()){
        //錯誤處理
        if (reply->error() == QNetworkReply::NoError)
        {
            qDebug() << "request protobufHttp NoError";
        }
        else
        {
            qDebug()<<"request protobufHttp handle errors here";
            QVariant statusCodeV = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
            //statusCodeV是HTTP伺服器的相應碼，reply->error()是Qt定義的錯誤碼，可以參考QT的文件
            qDebug() << "request protobufHttp found error ....code: %d %d\n" << statusCodeV.toInt() << (int)reply->error();
            emit m_request_fail(statusCodeV.toInt(),reply->errorString());
        }
    }else{
        qDebug() << "timeout";
        disconnect(m_requestTimeoutTimer,&QTimer::timeout,&eventLoop,&QEventLoop::quit);
        emit m_request_fail(-1,"timeout");
    }
    //請求返回的結果
    QByteArray response = reply->readAll();
    reply->abort(); reply->deleteLater();
    return response;
}