Qt網路編程之執行個體二POST方式

       上一篇文章主要介紹了Qt網路編程的GET方式，這裡再說一下POST方式。首先說一下自己的環境：

        主機：Win7；Web伺服器：TomCat v7.x；資料庫伺服器：MySQL v5.x。

        主要是用Qt實現登入驗證，後台使用servlet響應登入請求，查詢後台資料庫，是否為合法使用者。相信大家明白了吧！我實現的就是用戶端發出請求，伺服器端在資料庫中進行查詢，如果尋找到，則返回使用者資訊，如果沒有找到，則返回0，首先貼一下：

        1、在瀏覽器中測試：

         2、在Qt用戶端中測試：

        這裡貼一下Qt用戶端的代碼，伺服器端的代碼可詳見另一篇博文：Android Tomcat 的應用之伺服器部分

#include "mainwindow.h"#include "ui_mainwindow.h"#include <QNetworkReply>#include <QNetworkRequest>MainWindow::MainWindow(QWidget *parent) :    QMainWindow(parent),    ui(new Ui::MainWindow){    ui->setupUi(this);    nam = new QNetworkAccessManager(this);    QObject::connect(nam, SIGNAL(finished(QNetworkReply*)),             this, SLOT(finishedSlot(QNetworkReply*)));}MainWindow::~MainWindow(){    delete ui;}void MainWindow::on_pushButton_clicked(){    //QUrl url("http://www.hust.edu.cn/");    //QUrl url("http://www.google.com/ig/api?weather=wuhan");    QUrl url("http://localhost:8080/WebRoot/servlet/LoginServlet");    QByteArray append("username=admin&password=123456");    //QNetworkReply* reply = nam->get(QNetworkRequest(url));    QNetworkReply* reply = nam->post(QNetworkRequest(url), append);    // NOTE: Store QNetworkReply pointer (maybe into caller).    // When this HTTP request is finished you will receive this same    // QNetworkReply as response parameter.    // By the QNetworkReply pointer you can identify request and response.}void MainWindow::finishedSlot(QNetworkReply *reply){#if 1     // Reading attributes of the reply     // e.g. the HTTP status code     QVariant statusCodeV =     reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);     // Or the target URL if it was a redirect:     QVariant redirectionTargetUrl =     reply->attribute(QNetworkRequest::RedirectionTargetAttribute);     // see CS001432 on how to handle this     // no error received?     if (reply->error() == QNetworkReply::NoError)     {         // read data from QNetworkReply here         // Example 1: Creating QImage from the reply         //QImageReader imageReader(reply);         //QImage pic = imageReader.read();         // Example 2: Reading bytes form the reply         QByteArray bytes = reply->readAll();  // bytes         //QString string(bytes); // string         QString string = QString::fromUtf8(bytes);         ui->textBrowser->setText(string);     }     // Some http error received     else     {         // handle errors here     }     // We receive ownership of the reply object     // and therefore need to handle deletion.     reply->deleteLater();#endif}

              好了，今天就到這吧