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Qt对xml文件的读写

最近研究了一下qt下对xml文件的读写，小计一下，成为自己的知识。

main函数调用：

 1 #include <QApplication>
 2 #include "readconfig.h"
 3 #include "writeconfig.h"
 4 
 5 int main(int argc,char **argv)
 6 {
 7     QApplication a(argc,argv);
 8 
 9     //ReadConfig readConfig;
10 
11     //readConfig.changeSave();
12 
13     WriteConfig writeConfig;
14 
15     QFile file;
16     QString fileName = "Motor.xml";
17     if(!file.exists(fileName))
18     {
19         writeConfig.createFile(fileName);
20     }
21 
22     writeConfig.writeFile(fileName);
23 
24     a.exec();
25 
26     return 0;
27 }

写入xml文件WriteConfig.cpp

  1 #include "writeconfig.h"
  2 
  3 WriteConfig::WriteConfig()
  4 {
  5 }
  6 
  7 
  8 bool WriteConfig::writeFile(QString fileName)
  9 {
 10     QFile file(fileName);
 11 
 12     if(!file.open(QFile::ReadOnly | QFile::Text))
 13     {
 14         qDebug()<<"open for add error...";
 15         return false;
 16     }
 17 
 18     QDomDocument doc;
 19 
 20     QString errorStr;
 21     int errorLine;
 22     int errorColumn;
 23 
 24     if (!doc.setContent(&file, false, &errorStr, &errorLine, &errorColumn))
 25     {
 26            qDebug()<<"add setcontent error..." <<"errorStr&&&&"<<errorStr<<"errorLine"<<errorLine<<"errorColume"<<errorColumn;
 27            //file.close();
 28     }
 29 
 30 
 31     file.close();
 32 
 33     QDomElement root = doc.documentElement();
 34     if(root.isNull())
 35     {
 36         root = doc.createElement("configinfo");
 37     }
 38     QDomElement elementRoot = doc.createElement("motor");
 39     elementRoot.setAttribute("mount","6");
 40     QDomElement elementSpeed = doc.createElement("speed");
 41     QDomElement elementAcceleSpeed= doc.createElement("accelespeed");
 42     QDomElement elementAASpeed = doc.createElement("aaspeed");
 43     QDomElement elementPosition = doc.createElement("position");
 44 
 45     QDomElement elementV1 = doc.createElement("v");
 46     QDomElement elementV2 = doc.createElement("v");
 47     QDomElement elementV3 = doc.createElement("v");
 48     QDomElement elementV4 = doc.createElement("v");
 49     QDomElement elementV5 = doc.createElement("v");
 50     QDomElement elementV6 = doc.createElement("v");

 51     QDomElement elementA1 = doc.createElement("a");
 52     QDomElement elementA2 = doc.createElement("a");
 53     QDomElement elementA3 = doc.createElement("a");
 54     QDomElement elementA4 = doc.createElement("a");
 55     QDomElement elementA5 = doc.createElement("a");
 56     QDomElement elementA6 = doc.createElement("a");

 57     QDomElement elementAA1 = doc.createElement("aa");
 58     QDomElement elementAA2 = doc.createElement("aa");
 59     QDomElement elementAA3 = doc.createElement("aa");
 60     QDomElement elementAA4 = doc.createElement("aa");
 61     QDomElement elementAA5 = doc.createElement("aa");
 62     QDomElement elementAA6 = doc.createElement("aa");

 63     QDomElement elementP1 = doc.createElement("p");
 64     QDomElement elementP2 = doc.createElement("p");
 65     QDomElement elementP3 = doc.createElement("p");
 66     QDomElement elementP4 = doc.createElement("p");
 67     QDomElement elementP5 = doc.createElement("p");
 68     QDomElement elementP6 = doc.createElement("p");
 69 
 70 
 71     QDomText text;
 72     text = doc.createTextNode("123.25");
 73     elementV1.appendChild(text);
 74     elementSpeed.appendChild(elementV1);
 75     text = doc.createTextNode("223.25");
 76     elementV2.appendChild(text);
 77     elementSpeed.appendChild(elementV2);
 78     text = doc.createTextNode("323.25");
 79     elementV3.appendChild(text);
 80     elementSpeed.appendChild(elementV3);
 81     text = doc.createTextNode("423.25");
 82     elementV4.appendChild(text);
 83     elementSpeed.appendChild(elementV4);
 84     text = doc.createTextNode("523.25");
 85     elementV5.appendChild(text);
 86     elementSpeed.appendChild(elementV5);
 87     text = doc.createTextNode("623.25");
 88     elementV6.appendChild(text);
 89     elementSpeed.appendChild(elementV6);
 90 
 91     text = doc.createTextNode("1023.25");
 92     elementA1.appendChild(text);
 93     elementAcceleSpeed.appendChild(elementA1);
 94     text = doc.createTextNode("2023.25");
 95     elementA2.appendChild(text);
 96     elementAcceleSpeed.appendChild(elementA2);
 97     text = doc.createTextNode("3023.25");
 98     elementA3.appendChild(text);
 99     elementAcceleSpeed.appendChild(elementA3);
100     text = doc.createTextNode("4023.25");
101     elementA4.appendChild(text);
102     elementAcceleSpeed.appendChild(elementA4);
103     text = doc.createTextNode("5023.25");
104     elementA5.appendChild(text);
105     elementAcceleSpeed.appendChild(elementA5);
106     text = doc.createTextNode("6023.25");
107     elementA6.appendChild(text);
108     elementAcceleSpeed.appendChild(elementA6);
109 
110     text = doc.createTextNode("12.25");
111     elementAA1.appendChild(text);
112     elementAASpeed.appendChild(elementAA1);
113     text = doc.createTextNode("22.25");
114     elementAA2.appendChild(text);
115     elementAASpeed.appendChild(elementAA2);
116     text = doc.createTextNode("32.25");
117     elementAA3.appendChild(text);
118     elementAASpeed.appendChild(elementAA3);
119     text = doc.createTextNode("42.25");
120     elementAA4.appendChild(text);
121     elementAASpeed.appendChild(elementAA4);
122     text = doc.createTextNode("52.25");
123     elementAA5.appendChild(text);
124     elementAASpeed.appendChild(elementAA5);
125     text = doc.createTextNode("62.25");
126     elementAA6.appendChild(text);
127     elementAASpeed.appendChild(elementAA6);
128 
129     text = doc.createTextNode("12325");
130     elementP1.appendChild(text);
131     elementPosition.appendChild(elementP1);
132     text = doc.createTextNode("22325");
133     elementP2.appendChild(text);
134     elementPosition.appendChild(elementP2);
135     text = doc.createTextNode("32325");
136     elementP3.appendChild(text);
137     elementPosition.appendChild(elementP3);
138     text = doc.createTextNode("42325");
139     elementP4.appendChild(text);
140     elementPosition.appendChild(elementP4);
141     text = doc.createTextNode("52325");
142     elementP5.appendChild(text);
143     elementPosition.appendChild(elementP5);
144     text = doc.createTextNode("62325");
145     elementP6.appendChild(text);
146     elementPosition.appendChild(elementP6);
147 
148     text.clear();
149 
150     elementRoot.appendChild(elementSpeed);
151     elementRoot.appendChild(elementAcceleSpeed);
152     elementRoot.appendChild(elementAASpeed);
153     elementRoot.appendChild(elementPosition);
154     root.appendChild(elementRoot);
155 
156 
157 
158     if(!file.open(QIODevice::WriteOnly | QIODevice::Text))
159     {
160         qDebug()<<"open for add error!!";
161     }
162 
163     QTextStream out(&file);
164     doc.save(out,4);
165     file.close();
166     return true;
167 }
168 
169 
170 bool WriteConfig::createFile(QString fileName)
171 {
172     QFile file(fileName);
173     file.open(QIODevice::ReadWrite);
174     QDomDocument doc;
175     QDomProcessingInstruction instruction;
176     instruction = doc.createProcessingInstruction("xml","version="1.0" encoding="GB2312"");
177     doc.appendChild(instruction);
178     QDomElement root = doc.createElement("configinfo");
179 
180     doc.appendChild(root);
181     QDomText text = doc.createTextNode("");
182     root.appendChild(text);
183     QTextStream out(&file);
184     doc.save(out,4);
185     file.close();
186 }

读xml文件ReadConfig.cpp

  1 bool ReadConfig::openXmlFile(QString filePath)
  2 {
  3     QFile file(filePath);
  4     if( !file.open(QFile::ReadOnly | QFile::Text))
  5     {
  6        qDebug() << QObject::tr("error::ParserXML->OpenXmlFile->file.open->%s
") << filePath;
  7 
  8        return false;
  9     }
 10 
 11    if( !m_doc.setContent(&file))
 12    {
 13        qDebug() << QObject::tr("error::ParserXML->OpenXmlFile->doc.setContent
") << filePath;
 14 
 15        file.close();
 16        return false;
 17    }
 18    file.close();
 19    return true;
 20 }
 21 
 22 bool ReadConfig::changeSave()
 23 {
 24     QString fileName = "Motor.xml";
 25     if(!openXmlFile(fileName))
 26     {
 27         return false;
 28     }
 29     //修改保存xml
 30    QDomElement root = m_doc.documentElement();
 31    if(root.tagName()!= "configinfo")
 32        return false;
 33    QDomNode n = root.firstChild();
 34    while ( !n.isNull() )
 35    {
 36        QDomElement e = n.toElement();
 37        if( !e.isNull())
 38        {
 39            if( e.nodeName() == "motor" )
 40            {
 41                if(e.hasAttributes())
 42                {
 43                    QDomNamedNodeMap tmpMap = e.attributes();
 44                    for(int i = 0; i < (int)tmpMap.size();i++)
 45                    {
 46                        QString nodeName = tmpMap.item(i).nodeName();
 47                        QString nodeValue = tmpMap.item(i).nodeValue();
 48                        if("mount" == nodeName)
 49                        {
 50                            if(!nodeValue.isNull() && !nodeValue.isEmpty())
 51                            {
 52                                 jointNum = nodeValue.toInt();
 53                                 qDebug() << "************jointNum ="<<jointNum<<endl;
 54                            }
 55                        }
 56                    }
 57                }
 58                QDomNodeList list = e.childNodes(); //获得元素e的所有子节点的列表
 59                for(int a=0; a<list.count(); a++) //遍历该列表
 60                {
 61                    QDomNode node = list.at(a);
 62                    if(node.isElement())
 63                    {
 64                        if( node.nodeName() == "speed" )
 65                        {
 66                            if(node.hasChildNodes())
 67                            {
 68                                QDomNodeList speedList = node.childNodes();
 69                                for(int i = 0; i < speedList.size(); i++)
 70                                {
 71                                    if("v" == speedList.at(i).toElement().tagName())
 72                                    {
 73                                         qDebug()<<"****speedList***"<<speedList.at(i).toElement().text().toDouble();
 74                                    }
 75                                }
 76                            }
 77                        }
 78                        if( node.nodeName() == "accelespeed" )
 79                        {
 80                            if(node.hasChildNodes())
 81                            {
 82                                QDomNodeList speedList = node.childNodes();
 83                                for(int i = 0; i < speedList.size(); i++)
 84                                {
 85                                    if("a" == speedList.at(i).toElement().tagName())
 86                                    {
 87                                         qDebug()<<"****speedList***"<<speedList.at(i).toElement().text().toDouble();
 88                                    }
 89                                }
 90                            }
 91                        }
 92                        if(node.nodeName() == "aaspeed")
 93                        {
 94                            if(node.hasChildNodes())
 95                            {
 96                                QDomNodeList speedList = node.childNodes();
 97                                for(int i = 0; i < speedList.size(); i++)
 98                                {
 99                                    if("aa" == speedList.at(i).toElement().tagName())
100                                    {
101                                         qDebug()<<"****speedList***"<<speedList.at(i).toElement().text().toDouble();
102                                    }
103                                }
104                            }
105                        }
106                        if(node.nodeName() == "position")
107                        {
108                            if(node.hasChildNodes())
109                            {
110                                QDomNodeList speedList = node.childNodes();
111                                for(int i = 0; i < speedList.size(); i++)
112                                {
113                                    if("p" == speedList.at(i).toElement().tagName())
114                                    {
115                                         qDebug()<<"****speedList***"<<speedList.at(i).toElement().text().toLongLong();
116                                    }
117                                }
118                            }
119                        }
120                    }
121                }
122            }
123         }
124        n = n.nextSibling();
125       }
126      QFile filexml(fileName);
127      if( !filexml.open( QFile::WriteOnly | QFile::Truncate) )
128      {
129          qWarning("error::ParserXML->writeOperateXml->file.open
");
130          return false;
131       }
132     QTextStream ts(&filexml);
133     ts.reset();
134     ts.setCodec("utf-8");
135     m_doc.save(ts, 4, QDomNode::EncodingFromTextStream);
136     filexml.close();
137     return true;
138 }

xml文件

Motor.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <configinfo>
 3     <motor mount="6">
 4         <speed>
 5             <v>123.25</v>
 6             <v>223.25</v>
 7             <v>323.25</v>
 8             <v>423.25</v>
 9             <v>523.25</v>
10             <v>623.25</v>
11         </speed>
12         <accelespeed>
13             <a>1023.25</a>
14             <a>2023.25</a>
15             <a>3023.25</a>
16             <a>4023.25</a>
17             <a>5023.25</a>
18             <a>6023.25</a>
19         </accelespeed>
20         <aaspeed>
21             <aa>12.25</aa>
22             <aa>22.25</aa>
23             <aa>32.25</aa>
24             <aa>42.25</aa>
25             <aa>52.25</aa>
26             <aa>62.25</aa>
27         </aaspeed>
28         <position>
29             <p>12325</p>
30             <p>22325</p>
31             <p>32325</p>
32             <p>42325</p>
33             <p>52325</p>
34             <p>62325</p>
35         </position>
36     </motor>
37 </configinfo>

在使用的时候一定要注意路径问题，以上代码通过编译测试。

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原文地址：https://www.cnblogs.com/wanzaiyimeng/p/4616911.html