Question

我想做一个简单的帖子请求int main.cpp。看来，当我运行该应用程序时，它不会执行代码，只会跳过它。

我尝试使用qt调试器，但是调试器启动后，下面的代码恰好在此之后结束。

我已经用邮递员测试了我的api，并且知道它可以工作

main.cpp

#include <iostream>
#include <QNetworkReply>
#include <QNetworkAccessManager>
#include <QNetworkInterface>

using namespace std;
int main()
{
QByteArray jsonString = "{\"ipaddr\": "+ QByteArray::number(9) + ",\"transactionType\":"+QByteArray::number(10) + ",\"idEmployee\":"+QByteArray::number(10) +"}";


QNetworkRequest request(QUrl("http://192.168.1.25:3000/classlog/pi"));
request.setRawHeader("Content-Type", "application/json");

QNetworkAccessManager * manager = new QNetworkAccessManager();
manager->post(request, jsonString);

}

.pro

TEMPLATE = app
CONFIG += console c++11
CONFIG -= app_bundle
QT += network core

SOURCES += \
    main.cpp

我希望我能够在服务器中接收请求，但是我什么也没收到。谢谢

Answer 1

Qt使用事件系统。您的网络管理员将仅安排将在事件循环中处理的请求。这也是收到响应的地方。

您需要一个运行中的事件循环（实际上，一个QCoreApplication对象，在执行代码时会收到警告）。

#include <QtNetwork>

int main(int argc, char **argv)
{
    QCoreApplication app(argc, argv);
    QNetworkAccessManager mgr;
    QNetworkRequest req(QUrl("http://stackoverflow.com"));
    auto *resp = mgr.get(req);
    QObject::connect(resp, &QNetworkReply::finished, [&]() {
        qDebug() << "FINISHED";
        if (resp->error() != QNetworkReply::NoError)
            qDebug() << "Error: " << resp->errorString();
        else
            qDebug() << "Status: " << resp->attribute(QNetworkRequest::HttpStatusCodeAttribute).toString();

        // Stop when a response is received
        app.quit();
    });

    // This will start the event loop that will eventually send the request and receive the response.
    // It will run until you call app.quit()
    return app.exec();
}

Answer 2

您快到了：

connect the signals:

QtObject::connect(your_manager, SIGNAL(finished(QNetworkReply *)), this, SLOT(onResult(QNetworkReply *)));

send something:
QNetworkRequest request(your_URL);
request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
QByteArray byteArray;
byteArray.append(your_json);

your_manager->post(request, byteArray);


read the answer in the slot:
void FOO_CLASS::onResult(QNetworkReply* reply)
{
    QString resp = QString::fromUtf8(reply->readAll());
}

编辑：

QObject::connect(your_manager, &QNetworkAccessManager::finished, [](QNetworkReply * r){
    QString x{r->readAll()};
    //foo1
    auto l{x.length()};
    //foo2
});

如何在Qt main（）中运行发布请求

2 个答案: