在上一篇文章《用户登录及API调用的实现》中,我通过程序实现了用户登录及API调用的实现。从而能够实现网络查词、添词的操作。可是。从上文中能够看到。调用API后返回的是JSON格式的数据,例如以下图所看到的(在QtCreator中的显示): 
为了更好的观察JSON格式。我整理后显演示样例如以下: 
显然。为了显示查词的结果,我们必须在上图中提取实用的信息,并正确的显示出来。
上图中每一行内容的意思我已经在文章《调用网络API》中作了解释。我在词典中选择想要显示的内容有:单词本身、单词ID、中文解释、英文解释、音标、发音音频。与之相应上图中的content、learning_id、definition、en_definitions、pron、audio。
为了获取这些内容,我们必须进行对上面的JSON格式数据(关于什么是JSON格式,能够自己百度)进行解析。在Qt 4中,没有相应的模块,必须单独增加相应的函数库,当然也能够自己依据JSON的格式自己敲代码提取你想要的内容,仅仅只是比較麻烦而已。在Qt5中。自带有相应的JSON解析模块。因此不用自己来写解析函数了,仅仅须要调用相应的函数。以下给出详细的程序实现:
程序的主体框架与文章《用户登录及API调用的实现》中的一样,仅仅是在当中增加了JSON数据解析功能。
详细的说,每当发送查词请求后,server就会返回JSON格式的单词内容。因此,我们仅仅须要在处理server返回数据的函数replyfinished()函数中相应的查词操作QueryWordAction中进行JSON数据解析。将我们须要的内容存储到我们定义的Word类中。当中,word的定义例如以下: 
因为仅仅是在上文《用户登录及API调用的实现》的程序中加了JSON解析的部分,其他部分基本没变。所以程序的执行流程及思路可见上文。当然,程序中的凝视也算比較详细。因此不作详细说明。仅仅须要将以下五个源文件放入空的Qt项目中就可以。注意:是在Qt 5中,且须要在其.pro文件里增加语句:QT +=core gui network webkit multimedia。
详细的源文件例如以下:
1、word.h文件
#ifndef WORD_H
#define WORD_H
#include<QString>
#include<List>
#include <QJsonObject>
#include<QtMultimedia/QMediaPlayer>
#include<QUrl>
class Word
{
public:
    explicit Word();
    Word(const Word& word);
    ~Word();
public:
    QString name;//单词本身
    QString learning_id;//单词ID
    QString definition;//单词中文解释
    QString en_definitions;//单词英文解释
    QString pron;//单词音标
    QString audio;//单词的发音音频
    void clear();
};
#endif // WORD_H2、word.cpp文件
#include "word.h"
Word::Word()
{
}
Word::Word(const Word &w)
{
    name=w.name;
    learning_id=w.learning_id;
    definition=w.definition;
    en_definitions=w.en_definitions;
    pron=w.pron;
    audio=w.audio;
}
Word::~Word()
{
}
void Word::clear()//清除内容
{
    name="";
    learning_id="";
    definition="";
    en_definitions="";
    pron="";
    audio="";
   // this->examples=NULL;
}3、network.h文件
#ifndef NETWORK_H
#define NETWORK_H
#include"word.h"
#include <QObject>
#include <QtNetwork/QNetworkAccessManager>
#include<QtNetwork/QNetworkReply>
#include<QtNetwork/QNetworkRequest>
#include<QtNetwork/QNetworkCookie>
#include<QtNetwork/QNetworkCookieJar>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QJsonValue>
#include<QString>
#include<QDebug>
#include<QList>
#include<QUrl>
#include<QByteArray>
class netWork : public QObject
{
    Q_OBJECT
public:
    explicit netWork(QObject *parent = 0);
 //   ~netWork();
    enum HttpAction{NoAction,NetStudy,GetSessionidAction,LoginAction,QueryWordAction,AddWordAction,AddExampleAction,QueryWordExamplesAction};
    HttpAction httpAction;
    QNetworkAccessManager * http;
    QString sessionid;
    QString queryword;//要查询的单词
    QString nickname;
    QString username;
    QString password;
    bool isBusy;
    Word *gotword;//通过訪问网络得到的单词信息
    QString getCookie(const QString &name);
    void loginShanbay();
    void queryWord(const QString &word);
    void queryExamples(QString learningid);
    void connectNet(QString username="nineheadedbird", QString password="123456");
    void addWord(const QString &word);
signals:
    void signalQueryFinished(Word *word);
    void connectSuccess();
    void connectFail();
    void verifySuccess();
    void verifyFail();
    void NetState(bool);
public slots:
    void replyfinished(QNetworkReply*);
};
#endif // NETWORK_H
4、network.cpp文件
#include "network.h"
#include<QList>
#include<QDesktopServices>
netWork::netWork(QObject *parent) :
    QObject(parent)
{
        http=new QNetworkAccessManager(this);
        http->setCookieJar(new QNetworkCookieJar(this));
        connect(http,SIGNAL(finished(QNetworkReply*)),this,SLOT(replyfinished(QNetworkReply*)));
        isBusy=true;
        gotword=new Word();
}
QString netWork::getCookie(const QString &name)
{
    foreach(QNetworkCookie cookie , http->cookieJar()->cookiesForUrl(QUrl("http://www.shanbay.com/")))
    {
            //qDebug()<<cookie.name();
            if(cookie.name()==name)
            {
                return cookie.value();
            }
        }
        return "";
}
void netWork::loginShanbay()
{
       QNetworkRequest request;
       request.setUrl(QUrl("http://www.shanbay.com/accounts/login/"));
       request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
       request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
       request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
       request.setRawHeader("Cache-Control","max-age=0");
       request.setRawHeader("Connection","keep-alive");
       request.setRawHeader("Host","www.shanbay.com");
       request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
       request.setRawHeader("Origin","http//www.shanbay.com");
       request.setRawHeader("Referer","http://www.shanbay.com/accounts/login/");
       request.setRawHeader("Host","www.shanbay.com");
       request.setRawHeader("Content-Type","application/x-www-form-urlencoded");
       QByteArray postData;
       postData.append(QString("csrfmiddlewaretoken=%1&").arg(sessionid));
       postData.append(QString("username=%1&password=%2&").arg(QUrl::toPercentEncoding(username).constData()).arg(password));
       postData.append("login=登录&continue=home&u=1&next=");
       request.setHeader(QNetworkRequest::ContentLengthHeader,postData.size());
       httpAction=LoginAction;
       http->post(request,postData);
}
void netWork::queryWord(const QString &word)
{
      QNetworkRequest request;
      request.setUrl(QUrl("http://www.shanbay.com/api/word/"+word));
      request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
      request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
      request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
      request.setRawHeader("Cache-Control","max-age=0");
      request.setRawHeader("Connection","keep-alive");
      request.setRawHeader("Host","www.shanbay.com");
      request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
      httpAction=QueryWordAction;
      http->get(request);
}
void netWork::queryExamples(QString learningid)
{
    if(learningid=="0"){
           return;
       }
       QNetworkRequest request;
       request.setUrl(QUrl("http://www.shanbay.com/api/learning/examples/"+learningid));
       request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
       request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
       request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
       request.setRawHeader("Cache-Control","max-age=0");
       request.setRawHeader("Connection","keep-alive");
       request.setRawHeader("Host","www.shanbay.com");
       request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
       httpAction=QueryWordExamplesAction;
       http->get(request);
}
void netWork::addWord(const QString &word)
{
    if(word.isEmpty())
        qDebug()<<"你的输入有误";
    else
    {
        QNetworkRequest request;
        request.setUrl(QUrl("http://www.shanbay.com/api/learning/add/"+word));
        request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
        request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
        request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
        request.setRawHeader("Cache-Control","max-age=0");
        request.setRawHeader("Connection","keep-alive");
        request.setRawHeader("Host","www.shanbay.com");
        request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
        httpAction=AddWordAction;
        http->get(request);
    }
}
void netWork::connectNet(QString username, QString password)
{
        this->username=username;
        this->password=password;
         QNetworkRequest request;
        request.setUrl(QUrl("http://www.shanbay.com/accounts/login/"));
        request.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
        request.setRawHeader("Accept-Charset","GBK,utf-8;q=0.7,*;q=0.3");
        request.setRawHeader("Accept-Language","zh-CN,zh;q=0.8");
        request.setRawHeader("Cache-Control","max-age=0");
        request.setRawHeader("Connection","keep-alive");
        request.setRawHeader("Host","www.shanbay.com");
        request.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7");
        httpAction=GetSessionidAction;
        http->get(request);
}
void netWork::replyfinished(QNetworkReply *reply)
{
    QByteArray wordInformation;
    QVariant status_code=reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
 //  qDebug()<<"code_state="<<status_code;
    if(status_code==QVariant::Invalid)
        emit NetState(false);
    else
        emit NetState(true);
    QJsonDocument jsonDoc;
    QJsonObject jsonObj,vocObj,en_definitionsObj;
    switch(httpAction)
    {
    case NoAction:
        break;
    case GetSessionidAction:
        sessionid=getCookie("csrftoken");
        if(!sessionid.isEmpty()){
            emit connectSuccess();
            qDebug()<<("Connect successfully! Verifying username and password...");
           loginShanbay();
        }else{
            emit connectFail();
             qDebug()<<("Cannot connect! Please try to check the internet!");
        }
        break;
    case LoginAction:
        httpAction=NoAction;
        if(0==reply->readAll().size())
        {
            QString nickname=QUrl::fromPercentEncoding(getCookie("username").toLatin1());
            emit verifySuccess();
            qDebug()<<"Login successfully!"<<nickname;
            queryWord("hello");
        }else
        {
            emit verifyFail();
            qDebug()<<"Failed to login! Please check!";
        }
        break;
    case QueryWordAction://是在这里面进行JSON数据解析!
        qDebug()<<"----query word----";
        wordInformation=reply->readAll();
         qDebug()<<"the information of word in JSON format::\n";
         qDebug()<< wordInformation;
        jsonDoc=QJsonDocument::fromJson( wordInformation);
        if(!jsonDoc.isNull())
        {
            jsonObj=jsonDoc.object();
            vocObj=jsonObj.value("voc").toObject();//Qt5 自带JSON解析,因此非常easy得到单词的各个部分的内容
            en_definitionsObj=vocObj.value("en_definitions").toObject();   
            gotword->clear();
            gotword->name=vocObj.value("content").toString();//单词本身
            gotword->learning_id=QString::number(jsonObj.value("learning_id").toDouble(),‘g‘,15);
            gotword->definition=vocObj.value("definition").toString();//中文解释
            gotword->pron=vocObj.value("pron").toString();//单词音标
            gotword->pron=gotword->pron;
            gotword->audio=vocObj.value("audio").toString();
            //因为单词的英文解释有多项(词性、解释等等)。我们将结果用html格式表示。并使得词性颜色设置为黑色
            for( QJsonObject::const_iterator it=en_definitionsObj.constBegin();it!=en_definitionsObj.constEnd();it++)
            {
                gotword->en_definitions+=QString("<br><font color=‘black‘><b>%1. </b></font>").arg(it.key());
                if(it.value().isArray())
                {
                    foreach(QJsonValue jv,it.value().toArray())
                    {
                       gotword->en_definitions+=QString("%1; ").arg(jv.toString());
                    }
                }
                gotword->en_definitions+="<br>";
            }
            emit signalQueryFinished(gotword);
           //显示JSON解析后的数据
            qDebug()<<"name="<<gotword->name;
            qDebug()<<"word="<<gotword->learning_id;
            qDebug()<<"definition="<<gotword->definition;
            qDebug()<<"en_definitions="<<gotword->en_definitions;
            qDebug()<<"pron="<<gotword->pron;
            qDebug()<<"audio"<<gotword->audio;
            //进行网络发音
            QMediaPlayer *player = new QMediaPlayer();
                player->setMedia(QUrl(gotword->audio));
                player->play();
            if(gotword->learning_id!="0")//不是新单词
            {
                qDebug()<<"你学过这个单词";
            }
        }
        break;
    case QueryWordExamplesAction:
//            qDebug()<<"query word examples";
//             qDebug()<<reply->readAll();
            break;
    case AddWordAction:
//        qDebug()<<"add word";
        jsonDoc=QJsonDocument::fromJson(reply->readAll());
        if(!jsonDoc.isNull())
        {
            jsonObj=jsonDoc.object();
            //qDebug()<<"jsonObj"<<jsonObj;
            gotword->learning_id=QString::number(jsonObj.value("id").toDouble(),‘g‘,15);
          //  qDebug()<<jsonObj.value("id").toDouble()<<"add word result learning id="<<gotword->learning_id<< (gotword->learning_id!="0");
         //   emit signalAddwordFinished(DICT::word->learning_id!="0");
         //   queryExamples(DICT::word->learning_id);
        }
    default:break;
    }
}
5、main.cpp文件
#include <QApplication>
#include "network.h"
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    netWork *nW = new netWork();
    nW->connectNet();
    return a.exec();
}执行结果例如以下图: 
作品下载地址(公布版):http://download.csdn.net/detail/tengweitw/8548767 
作品下载地址(绿色版):http://download.csdn.net/detail/tengweitw/8830495 
源代码下载地址:http://download.csdn.net/detail/tengweitw/8830503
原文:http://blog.csdn.net/tengweitw/article/details/46506945 
作者:nineheadedbird
【Qt编程】基于Qt的词典开发系列<九>--JSON数据解析
原文:http://www.cnblogs.com/jzdwajue/p/7181340.html