Qt5 xml转Json

来源：互联网发布：js elementHTML 编辑：程序博客网时间：2024/06/13 09:49

由于业务需要，把xml数据转化为 json数据。

这个例子展示了 Qt的QDom解析xml 以及 QJson的用法。

xml

<?xml version="1.0" encoding="utf-8"?><root>   <mission title="有序列表中，Type属性可能的赋值是：" mid="11">    <answer result="0" aid="42">disc</answer>    <answer result="0" aid="44">circle</answer>    <answer result="1" aid="45">a</answer>    <answer result="0" aid="43">square</answer>  </mission>  <mission title="以下符号中，输出一根水平线条的标签是：" mid="2">    <answer result="0" aid="8"><line/></answer>    <answer result="1" aid="6"><hr/></answer>    <answer result="0" aid="7"><img/></answer>    <answer result="0" aid="5"><br/></answer>   </mission>    <mission title="HTML的基本结构是：" mid="3">    <answer result="0" aid="10"><root><head></head><body></body></root></answer>    <answer result="0" aid="11"><html><title></title><body></body></html></answer>    <answer result="1" aid="9"><html><head></head><body></body></html></answer>    <answer result="0" aid="12"><root><title></title><body></body></root></answer>   </mission>    <mission title="用来给网页增加背景图片的属性是：" mid="7">    <answer result="0" aid="27">src</answer>    <answer result="0" aid="26">bgcolor</answer>    <answer result="0" aid="28">image</answer>    <answer result="1" aid="29">background</answer>   </mission>    <mission title="超链接标签是：" mid="8">    <answer result="0" aid="31"><font></font></answer>    <answer result="0" aid="33"><em></em></answer>    <answer result="1" aid="30"><a></a></answer>    <answer result="0" aid="32"><link></link></answer>  </mission>  <code>1</code>  <mess>成功发送答题信息</mess> </root>

C++代码：

  QString str=reply->readAll();    QDomDocument doc;    doc.setContent(str);    QDomElement elem=doc.documentElement();    QDomNodeList Missions=elem.elementsByTagName("mission");    QJsonArray JsonArray;    QDomNodeList tmpNodes;    for(int i=0;i<=Missions.length();i++)    {       tmpNodes=Missions.at(i).toElement().elementsByTagName("answer");       QJsonObject tmpAnserJson;       QJsonArray tmparray;       for(int k=0;k<tmparray.count();k++)tmparray.removeAt(k);       tmpAnserJson.insert("title",Missions.at(i).toElement().attributeNode("title").value());        tmpAnserJson.insert("mid",Missions.at(i).toElement().attributeNode("mid").value());        for(int j=0;j<tmpNodes.length();j++)        {            QJsonObject tmpjsonObj;            tmpjsonObj.insert("answer",tmpNodes.at(j).toElement().text());            tmpjsonObj.insert("result",tmpNodes.at(j).toElement().attributeNode("result").value());            tmpjsonObj.insert("aid",tmpNodes.at(j).toElement().attributeNode("aid").value());            tmparray.append(tmpjsonObj);        }        tmpAnserJson.insert("detail",tmparray);        JsonArray.append(tmpAnserJson);    }    QJsonDocument jsondoc;    jsondoc.setArray(JsonArray);    QString strjson=jsondoc.toJson();    qDebug()<<strjson;    qDebug()<<str;

json：

[    {        "detail": [            {                "aid": "45",                "answer": "a",                "result": "1"            },            {                "aid": "42",                "answer": "disc",                "result": "0"            },            {                "aid": "44",                "answer": "circle",                "result": "0"            },            {                "aid": "43",                "answer": "square",                "result": "0"            }        ],        "mid": "11",        "title": "有序列表中，Type属性可能的赋值是："    },    {        "detail": [            {                "aid": "33",                "answer": "<em></em>",                "result": "0"            },            {                "aid": "30",                "answer": "<a></a>",                "result": "1"            },            {                "aid": "31",                "answer": "<font></font>",                "result": "0"            },            {                "aid": "32",                "answer": "<link></link>",                "result": "0"            }        ],        "mid": "8",        "title": "超链接标签是："    },    {        "detail": [            {                "aid": "17",                "answer": "<p></p>",                "result": "0"            },            {                "aid": "13",                "answer": "<hr/>",                "result": "0"            },            {                "aid": "16",                "answer": "<font></font>",                "result": "0"            },            {                "aid": "14",                "answer": "<h3></h3>",                "result": "1"            },            {                "aid": "15",                "answer": "<t></t>",                "result": "0"            }        ],        "mid": "4",        "title": "下列哪一个属于标题标签："    },    {        "detail": [            {                "aid": "38",                "answer": "<ol></ol>",                "result": "1"            },            {                "aid": "40",                "answer": "<dl></dl>",                "result": "0"            },            {                "aid": "41",                "answer": "<list></list>",                "result": "0"            },            {                "aid": "39",                "answer": "<ul></ul>",                "result": "0"            }        ],        "mid": "10",        "title": "有序列表的标签为："    },    {        "detail": [            {                "aid": "4",                "answer": "<huanhang/>",                "result": "0"            },            {                "aid": "1",                "answer": "<br/>",                "result": "1"            },            {                "aid": "2",                "answer": "<hr/>",                "result": "0"            },            {                "aid": "3",                "answer": "<img/>",                "result": "0"            }        ],        "mid": "1",        "title": "以下符号中，强制换行标签是："    },    {        "detail": [],        "mid": "",        "title": ""    }]

需要注意几点：

一。关于XML

xml获取根结点：（元素）

doc.documentElement();

结点，分文本结点，属性结点..

而元素是一种特别的结点，有文本和属性。

QDomNode 结点转元素需要

.toElement()

获取某一元素下面的元素，通过TagName（多个）

 QDomNodeList Missions=elem.elementsByTagName("mission");

获取元素的某个属性值：

.attributeNode("title").value()

二.关于Json

Json对象是：

 QJsonObject

在对象上插入属性（可以插入多个，多个属性）

 tmpjsonObj.insert("answer",tmpNodes.at(j).toElement().text());

值可以是对象，也可以是JsonArray，也可以是字符串。

Json数组是

QJsonArray tmparray;

数组不是键/值方式存储，直接插入即可。取出直接索引.

tmparray.append(tmpjsonObj);

作者原创，请勿转载。

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