Qt通过http发送json信息
Qt
已知请求地址和参数格式如下，将本地的信息发送出去。
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| http:
{
"barcode":"code1",
"weight":"1.1",
"length":"2.2",
"width":"3.3",
"height":"4.4"
}
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需要使用QNet，核心代码如下：
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| QUrl url("http://abc.efg.net/ijk?lmn=pqr");
QByteArray array("{\"barcode\":\"ceshi123\nceshi456\",\"weight\":1.11,\"length\":2.22,\"width\":3.33,\"height\":4.44}");
QNetworkRequest request(url);
request.setHeader(QNetworkRequest::ContentTypeHeader,QVariant("application/json"));
manager->post(request,array);
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对于Json格式，Qt有自己的类进行支持：
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| QJsonObject _exampleObject;
_exampleObject.insert("barcode", "ceshi123ceshi456");
_exampleObject.insert("weight", 11.225);
_exampleObject.insert("length", 45.6699);
_exampleObject.insert("width", 0.1);
_exampleObject.insert("height", 1000.456);
m_httpDocum->setObject(_exampleObject);
m_httpData = m_httpDocum->toJson(QJsonDocument::Compact);
QUrl url("http://abc.efg.net/ijk?lmn=pqr");
QNetworkRequest request(url);
request.setHeader(QNetworkRequest::ContentTypeHeader,QVariant("application/json"));
m_network->post(request,m_httpData);
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注意：因为QJsonObject内部应该是用Hashmap来存储的，所以输出是按key的ASCII码排序来的，可能与要求的顺序不一致，从而导致接收端报错。
另外，jsonArray中插入值的顺序与文件中的顺序是一致的，本身就是数组，自带下标（索引）。
插入值的代码：
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QJsonArray versionArray;
versionArray.append(4.8);
versionArray.append(5.2);
versionArray.append(5.7);
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结果：
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| "Version": [
4.8,
5.2,
5.7
]
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但是这种方式没有key值，不符合本次要求。
所以还是采用直接QByteArray的方式，为具有拓展性，可以采用QString的arg函数。
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| QString barcode = "ceshi123ceshi456";
double weight = 1.11;
double length = 2.22;
double width = 3.33;
double height = 4.44;
QString str = tr("{\"barcode\":\"%1\",\"weight\":%2,\"length\":%3,\"width\":%4,\"height\":%5}").arg(barcode).arg(weight).arg(length).arg(width).arg(height);
QByteArray arr = str.toUtf8();
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完整代码如下：
pro：
mainwindow.h
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| #ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QNetworkAccessManager>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QJsonObject>
#include <QJsonDocument>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
void getHtml(QString url);
public slots:
void replyFinished(QNetworkReply* reply);
private slots:
void on_POSTBtn_1_clicked();
private:
Ui::MainWindow *ui;
QNetworkAccessManager* m_network;
QJsonDocument* m_httpDocum;
QByteArray m_httpData;
};
#endif
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mainwindow.cpp
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| #include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
m_network = new QNetworkAccessManager(this);
connect(m_network,&QNetworkAccessManager::finished,this,&MainWindow::replyFinished);
m_httpDocum = new QJsonDocument();
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::getHtml(QString url)
{
m_network->get(QNetworkRequest(QUrl(url)));
}
void MainWindow::replyFinished(QNetworkReply *reply)
{
qDebug() << QString(reply->readAll());
}
void MainWindow::on_POSTBtn_1_clicked()
{
QUrl url("http://abc.efg.net/ijk?lmn=pqr");
QString barcode = "ceshi123ceshi456";
double weight = 1.11;
double length = 2.22;
double width = 3.33;
double height = 4.44;
QString str = tr("{\"barcode\":\"%1\",\"weight\":%2,\"length\":%3,\"width\":%4,\"height\":%5}").arg(barcode).arg(weight).arg(length).arg(width).arg(height);
QByteArray arr = str.toUtf8();
QNetworkRequest request(url);
request.setHeader(QNetworkRequest::ContentTypeHeader,QVariant("application/json"));
m_network->post(request,arr);
}
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main.cpp
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| #include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
QString url = "http://abc.efg.net/ijk?lmn=pqr";
w.getHtml(url);
return a.exec();
}
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