今天我们介绍一下QT的http请求，这里有post和get两种方式
一、post请求方式：参数分为网址和具体请求值两个部分，有时候还需要设置头信息，看具体情况定
1 void MainWindow::sendPostRequest()
2 {
3 QNetworkAccessManager *m_pHttpMgr = new QNetworkAccessManager();
4 //设置url
5 QString url = "http://10.0.0.20:8005/order/charge";
6 //设置头信息
7 QNetworkRequest requestInfo;
8 requestInfo.setUrl(QUrl(url));
9 requestInfo.setHeader(QNetworkRequest::ContentTypeHeader,QVariant("application/json"));
10 // requestInfo.setRawHeader("Content-Type","application/json");//服务器要求的数据头部
11 // requestInfo.setRawHeader("Accept","text/json,*/*;q=0.5");//服务器要求的数据头部
12
13 //发送数据
14 QByteArray qByteHttpData = sendJson();
15 QNetworkReply *reply = m_pHttpMgr->post(requestInfo, qByteHttpData);
16 //添加事件循环机制，返回后再运行后面的
17 QEventLoop eventLoop;
18 connect(reply, SIGNAL(finished()), &eventLoop, SLOT(quit()));
19 eventLoop.exec(); //block until finish
20
21 //错误处理
22 if (reply->error() == QNetworkReply::NoError)
23 {
24 qDebug() << "request protobufHttp NoError";
25 }
26 else
27 {
28 qDebug()<<"request protobufHttp handle errors here";
29 QVariant statusCodeV = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
30 //statusCodeV是HTTP服务器的相应码，reply->error()是Qt定义的错误码，可以参考QT的文档
31 qDebug( "request protobufHttp found error ....code: %d %d\n", statusCodeV.toInt(), (int)reply->error());
32 qDebug(qPrintable(reply->errorString()));
33 }
34
35 //请求收到的结果
36 QByteArray responseByte = reply->readAll();
37 ｝
二、get请求方式：参数和网址拼接到一起请求
1 void MainWindow::sendGetRequest()
2 {
3 QNetworkAccessManager *m_pHttpMgr = new QNetworkAccessManager();
4 //设置url
5 QString url = "http://10.0.0.20:8005/vending_machine/items/ac83f39ea268";//fae4b325e52c
6 QNetworkRequest requestInfo;
7 requestInfo.setUrl(QUrl(url));
8
9 //添加事件循环机制，返回后再运行后面的
10 QEventLoop eventLoop;
11 QNetworkReply *reply = m_pHttpMgr->get(requestInfo);
12 connect(reply, SIGNAL(finished()), &eventLoop, SLOT(quit()));
13 eventLoop.exec(); //block until finish
14 //错误处理
15 if (reply->error() == QNetworkReply::NoError)
16 {
17 qDebug() << "request protobufHttp NoError";
18 }
19 else
20 {
21 qDebug()<<"request protobufHttp handle errors here";
22 QVariant statusCodeV = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
23 //statusCodeV是HTTP服务器的相应码，reply->error()是Qt定义的错误码，可以参考QT的文档
24 qDebug( "request protobufHttp found error ....code: %d %d\n", statusCodeV.toInt(), (int)reply->error());
25 qDebug(qPrintable(reply->errorString()));
26 }
27 //请求返回的结果
28 QByteArray responseByte = reply->readAll();
29 qDebug() << responseByte;
30 ｝
三、主要区别：
get用于请求获取数据，post向指定的资源创建修改数据
get把参数包含在URL中（长度有限制），POST通过请求实体传递参数（安全）
