QT发送Get请求并返回内容

使用对象

1 QNetworkAccessManager--网络操作的管理者；

2 QNetworkRequest--网络请求的对象，用于接收url；

3 QNetworkReply--get或者post请求后的实体，实体会异步的进行数据的接收，需要手动销毁。

模块配置

QT += network

头文件

#include 
#include 

 函数实现

/**
 * @brief receive_getReply
 * @param reply
 * 处理回答
 */
void receive_getReply(QNetworkReply *reply) {
    if (nullptr == reply) {
        qDebug() << "reply nullptr";
        return;
    }
 
    /// 等待结束后再read
    QObject::connect(reply, &QNetworkReply::finished, [reply]() {
        /// read data
        QByteArray byte = reply->readAll();
        // reply->disconnect();
        /// delete pointer
        reply->deleteLater();
 
        /// data to json
        QJsonDocument jsonDocument = QJsonDocument::fromJson(byte.data());
 
        /// process data
        /// can emit in class::QObject
        qDebug() << jsonDocument;
    });
}

/**
 * @brief request_get
 * @param url
 * 查询，get请求
 * 注意，下方的QNetworkAccessManager 是静态对象
 */
void request_get(const QUrl &url) {
    static QNetworkAccessManager manager;
    QNetworkRequest request(url);
    QNetworkReply *reply = manager.get(request);
    receive_getReply(reply);
 
    // QEventLoop loop;
    /// [1]
    // QObject::connect(&manager, &QNetworkAccessManager::finished, &loop, &QEventLoop::quit);
    /// [2]
    // QObject::connect(reply, &QNetworkReply::finished, &loop, &QEventLoop::quit);
    // loop.exec();
}

/**
 * @brief test_network
 * 测试fun
 */
void test_network() {
    /// 天气预报查询api
    /// 首尾不要用空格
    QString url = R"(http://api.k780.com:88/?app=weather.future
                    &appkey=10003
                    &sign=b59bc3ef6191eb9f747dd4e83c99f2a4
                    &format=json
                    &weaid=苏州)";
    request_get(QUrl(url));
}