4. Send http request

4.1 copy mynetworkobject.cpp and mynetworkobject.h to your project

(ps: these two documents were found on the Internet, and I have modified them)

4.2 add "mynetworkobject.h" to the header file

// I added it in mainwindow.h (no special explanation below, take this demo as an example)
#include "mynetworkobject.h"

4.3 define a networkObj variable in mainwindow.h

//In public
MyNetworkObject *networkObj;

4.4 add a method of request success and failure in mainwindow.h.

public slots:
    void requestFail(QString str); //This method is triggered when a "failure signal" is sent
    void requestSuccess(QString str);//This method is triggered when a "success signal" is sent
};

4.5 and implement the two slot functions in mainwindow.cpp

void MainWindow::requestFail(QString str)
{
    qDebug() << "----------requestFail-------------";
    qDebug() << str;
}

void MainWindow::requestSuccess(QString str)
{
    qDebug() << "----------requestSuccess-------------";
    qDebug() << str;
}

4.6 add in the constructor of mainwindow.cpp

    networkObj = new MyNetworkObject(); //Create network objects
    connect(networkObj,SIGNAL(requestSuccessSignal(QString)),this,SLOT(requestSuccess(QString))); //Request success signal connection request success method
    connect(networkObj,SIGNAL(requestFailSignal(QString)),this,SLOT(requestFail(QString)));     //fail

    QUrl url("http://1.aosik.applinzi.com/demo/api/getUuid.php"); //Request address
    networkObj->get(url); //Send get request

Note: these two signals are defined in the mynetworkobject.h header file. The name can be changed, but remember that other places that use this signal should also be changed together

// Add two signals
signals:
    void requestFailSignal(QString str); //Send this signal when the request fails
    void requestSuccessSignal(QString str); //Send this signal when the request is successful

4.7 add QT + = network to pro file of the project

QT       += network

4.8 add mynetworkobject.cpp to SOURCES and mynetworkobject. H. to HEADERS in the pro file of the project. (PS: remember to add a backslash after the previous sentence. Remember to follow its writing rules. )

SOURCES += main.cpp\
        mainwindow.cpp\
        mynetworkobject.cpp 

HEADERS  += mainwindow.h\
            mynetworkobject.h

FORMS    += mainwindow.ui

Test and rebuild to see if the two files are related in the project. No means failure. Check it carefully.

4.9 if you don't change the signal name I wrote in this step, you don't need to change it.

    if(reply->error() == QNetworkReply::NoError) {
        qDebug()<<"NoError";
        QByteArray buffer = reply->readAll();
        dataStr = QString::fromUtf8(buffer);
        emit requestSuccessSignal(dataStr); //Trigger success signal here
    } else {
        emit requestFailSignal(reply->errorString());  //Trigger failure signal here
    }
    reply->deleteLater();

Let's test the get request together

Here is the log information, perfect!

Debug start
get   QUrl( "http://1.aosik.applinzi.com/demo/api/getUuid.php" )  
"HttpStatusCodeAttribute = 200" 
"HttpReasonPhraseAttribute = OK" 
NoError 
----------requestSuccess------------- 
"{"uuid":"123456789"}" 

I unplug the cable and test it

Debug start
get   QUrl( "http://1.aosik.applinzi.com/demo/api/getUuid.php" )  
"HttpStatusCodeAttribute = " 
"HttpReasonPhraseAttribute = " 
----------requestFail------------- 
"Host 1.aosik.applinzi.com not found" 

HOHO, yes~~~

Attach the php code for that test interface

<?php
/**
 * User: WiFi
 * Date: 2018/03/05
 * Time: 09:23
 */
$data = array(
'uuid' => '123456789'
);
//$data = 123456789;
$data = json_encode($data); 
echo $data;

demo address: https://github.com/WiFiUncle/blog/tree/master/qtDemo