QT中XML增删改查，不会有重复beta

最近在做QT项目，要把一些配置内容写入xml中，网上没有一个可以概括xml增删改查的内容，现在写一篇，包含完整的增删改查，测试通过，具体代码如下：

其中的测试代码见mainwindows.cpp里面，里面有创建xml文件，增加数据，删除数据，修改数据，查询数据，其中没有重复内容。删除的时候也把相同的标签全部删掉了。

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    XMLParser *xmlparser = new XMLParser("D:/","test.xml");

    QFile *file;
    //QString  filename = "D:/test.xml";
    if(!file->exists("D:/test.xml"))  {
        xmlparser->create_xml("D:/","test.xml");

    }
    bool ret = xmlparser->add_element("D:/","test.xml","password","12345");

    QString password = xmlparser->get_element("D:/","password");

    qDebug()<<"password is "<<password;

    bool ret01 = xmlparser->update_element("D:/","342345");


    bool ret02 = xmlparser->delete_element("D:/","1212342345");
    qDebug()<<"ret02 is "<<ret02;

    bool ret03 = xmlparser->delete_element("D:/","342345");
    qDebug()<<"ret03 is "<<ret03;

//    QString path = xmlparser->get_savepath();

//    if(NULL==path||path==""){
//        QString fileName = QFileDialog::getExistingDirectory(this,tr("请选择保存目录"),//                                                          "",//                                                       QFileDialog::ShowDirsOnly
//                                                          | QFileDialog::DontResolveSymlinks);
//        qDebug()<<"fileName is "<<fileName;
//        bool ret = xmlparser->set_savepath(fileName);
//        qDebug()<<"ret is "<<ret;
//    }else{
//        qDebug()<<"path is "<<path;
//    }


}

MainWindow::~MainWindow()
{

    delete ui;
}

xmlparser.cpp @H_403_12@#include "xmlparser.h" #define __XMLPARSER_DEBUG__ XMLParser::XMLParser(QObject *parent) : QObject(parent) { configPath = dir.currentPath()+"/setting.xml"; file=new QFile(configPath); } XMLParser::XMLParser(QString filepath,QString filename,QObject *parent) : QObject(parent) { this->filepath = filepath; this->filename=filename; } QString XMLParser::get_savepath(){ QDomDocument dom; if(file->open(QIODevice::ReadOnly)) { dom.setContent(file); }else{ return NULL; } QDomNodeList save_path=dom.elementsByTagName("save_path"); int elementnum = save_path.count(); QString savepath = save_path.item(0).toElement().text(); file->close(); if(NULL!=savepath&&savepath!=""){ return savepath; }else{ return NULL; } } bool XMLParser::set_savepath(QString path){ if(NULL==path||path==""){ return false; } if(!file->open(QIODevice::WriteOnly|QIODevice::ReadOnly)) { return false; } QDomDocument doc; QDomText text; QDomElement element; QDomProcessingInstruction instruction; instruction=doc.createProcessingInstruction("xml","version=\'1.0\'"); doc.appendChild(instruction); QDomElement root=doc.createElement("root"); doc.appendChild(root); QDomElement general=doc.createElement("general"); root.appendChild(general); element=doc.createElement("save_path"); text=doc.createTextNode(path); element.appendChild(text); general.appendChild(element); QTextStream out(file); doc.save(out,4); file->close(); return true; } QString XMLParser::get_element(QString filepath,QString elementstr){ if(NULL==filepath||NULL==filename||NULL==elementstr){ return NULL; } QString Path = filepath+filename; //QString Path = filepath.endsWith("/")?filepath+filename:filepath.mid(0,filepath.length()-1);+filename; QFile myfile(Path); QDomDocument dom; if(myfile.open(QIODevice::ReadOnly)) { QString errorStr; int errorLine; int errorColumn; //QDomDocument doc; if (!dom.setContent(&myfile,false,&errorStr,&errorLine,&errorColumn)) { #ifdef __XMLPARSER_DEBUG__ qDebug()<<"setcontent error..."<<" errorStr is "<<errorStr<<" errorLine is "<<errorLine<<" errorColumn is "<<errorColumn ; #endif myfile.close(); } myfile.close(); //dom.setContent(myfile); }else{ #ifdef __XMLPARSER_DEBUG__ qDebug()<<"open xml read error..." ; #endif return NULL; } QDomElement root = dom.documentElement(); if (root.tagName() != "root") { #ifdef __XMLPARSER_DEBUG__ qDebug()<<"root.tagname != root..." ; #endif } QDomNode node = root.firstChild(); while(!node.isNull()) { if(node.isElement()){ QDomElement element = node.toElement(); #ifdef __XMLPARSER_DEBUG__ qDebug()<<"tagName is "<<element.tagName()<<" element.text is "<<element.text(); #endif if(element.tagName()==elementstr){ return (element.text().length()>0&&NULL!=element.text())?element.text():NULL; } } node = node.nextSibling(); } return NULL; // QDomNodeList save_path=dom.elementsByTagName(element); // int elementnum = save_path.count(); // QString savepath = save_path.item(0).toElement().text(); // myfile->close(); // if(NULL!=savepath&&savepath!=""){ // return savepath; // }else{ // return NULL; // } } bool XMLParser::add_element(QString filepath,QString element,QString value){ #ifdef __XMLPARSER_DEBUG__ qDebug()<<"in add_element"; #endif if(NULL==filepath||NULL==filename||NULL==element||NULL==value){ return NULL; } //QString Path = filepath.endsWith("/")?filepath+filename:filepath.mid(0,filepath.length()-1);+filename; QString Path = filepath+filename; QFile myfile(Path); if(!myfile.open(QIODevice::WriteOnly|QIODevice::ReadOnly)) { return false; } QDomDocument doc; QString errorStr; int errorLine; int errorColumn; if (!doc.setContent(&myfile,&errorColumn)) { #ifdef __XMLPARSER_DEBUG__ qDebug()<<"setcontent error..."<<" errorStr is "<<errorStr<<" errorLine is "<<errorLine<<" errorColumn is "<<errorColumn ; #endif myfile.close(); } myfile.close(); QDomElement root = doc.documentElement(); if(root.isNull()) { root = doc.createElement("root"); } bool if_exist = false; QDomNode node = root.firstChild(); while(!node.isNull()) { if(node.isElement()){ QDomElement local_element = node.toElement(); #ifdef __XMLPARSER_DEBUG__ qDebug()<<"tagName is "<<local_element.tagName()<<" element.text is "<<local_element.text(); #endif if(local_element.tagName()==element){ if_exist = true; break; } } node = node.nextSibling(); } if(!if_exist){ QDomElement element_my = doc.createElement(element); QDomText text; text =doc.createTextNode(value); element_my.appendChild(text); root.appendChild(element_my); } #ifdef __XMLPARSER_DEBUG__ qDebug()<<"element is "<<element; qDebug()<<"value is "<<value; #endif if(!myfile.open(QIODevice::WriteOnly)){ #ifdef __XMLPARSER_DEBUG__ qDebug() << "open for add error!"; #endif } QTextStream out(&myfile); doc.save(out,4); myfile.close(); return true; } void XMLParser::create_xml(QString filepath,QString filename){ #ifdef __XMLPARSER_DEBUG__ qDebug()<<"in create_xml"; #endif if(NULL==filepath||NULL==filename){ return; } QString Path = filepath+filename; //QString Path = filepath.endsWith("/")?filepath+filename:filepath.mid(0,filepath.length()-1);+filename; QFile myfile(Path); myfile.open(QIODevice::ReadWrite); QDomDocument doc; QDomProcessingInstruction instruction; instruction = doc.createProcessingInstruction("xml","version=\'1.0\'"); doc.appendChild(instruction); QDomElement root = doc.createElement("root"); doc.appendChild(root); QDomText text = doc.createTextNode(""); root.appendChild(text); QTextStream out(&myfile); doc.save(out,4); myfile.close(); return; } bool XMLParser::update_element(QString filepath,QString value){ bool if_sucess = false; if(NULL==filepath||NULL==filename||NULL==element||NULL==value){ return false; } QString Path = filepath+filename; QFile myfile(Path); QDomDocument doc; QString errorStr; int errorLine; int errorColumn; if (!doc.setContent(&myfile,&errorColumn)) { #ifdef __XMLPARSER_DEBUG__ qDebug()<<"setcontent error..."<<" errorStr is "<<errorStr<<" errorLine is "<<errorLine<<" errorColumn is "<<errorColumn ; #endif myfile.close(); } myfile.close(); QDomElement root = doc.documentElement(); QDomNodeList lists = doc.elementsByTagName(element); //新建节点 QDomElement newNodeTag = doc.createElement(element); QDomText newNodeText = doc.createTextNode(value); newNodeTag.appendChild(newNodeText); int num = 0; for(num = 0;num<lists.size();num++){ QDomElement ele = lists.at(num).toElement(); #ifdef __XMLPARSER_DEBUG__ qDebug() << "element text is "<<ele.text(); #endif //把老的节点替换成新建节点 root.replaceChild(newNodeTag,ele); if_sucess = true; #ifdef __XMLPARSER_DEBUG__ qDebug() << "modify ok ! value is "<<value; #endif } if(!myfile.open(QIODevice::WriteOnly | QIODevice::Text)) { #ifdef __XMLPARSER_DEBUG__ qDebug() << "open for remove error!"; #endif } QTextStream out(&myfile); doc.save(out,4); myfile.close(); if(if_sucess){ return if_sucess; }else{ return if_sucess; } // return true; } bool XMLParser::delete_element(QString filepath,QString value){ if(NULL==filepath||NULL==filename||NULL==element||NULL==value){ return false; } QString Path = filepath+filename; bool if_sucess = false; QFile myfile(Path); QDomDocument doc; QString errorStr; int errorLine; int errorColumn; if (!doc.setContent(&myfile,&errorColumn)) { #ifdef __XMLPARSER_DEBUG__ qDebug()<<"setcontent error..."<<" errorStr is "<<errorStr<<" errorLine is "<<errorLine<<" errorColumn is "<<errorColumn ; #endif myfile.close(); } myfile.close(); QDomElement root = doc.documentElement(); QDomNodeList lists = doc.elementsByTagName(element); //新建节点 QDomElement newNodeTag = doc.createElement(element); QDomText newNodeText = doc.createTextNode(value); newNodeTag.appendChild(newNodeText); int num = 0; for(num = 0;num<lists.size();num++){ QDomElement ele = lists.at(num).toElement(); #ifdef __XMLPARSER_DEBUG__ qDebug() << "element text is "<<ele.text(); #endif //删除节点 if(ele.text()==value){ root.removeChild(ele); if_sucess = true; } #ifdef __XMLPARSER_DEBUG__ qDebug() << "modify ok ! value is "<<value; #endif } if(!myfile.open(QIODevice::WriteOnly | QIODevice::Text)) { #ifdef __XMLPARSER_DEBUG__ qDebug() << "open for remove error!"; #endif } QTextStream out(&myfile); doc.save(out,4); myfile.close(); if(if_sucess){ return if_sucess; }else{ return if_sucess; } } XMLParser::~XMLParser(){ if(NULL!=file){ file->close(); file=NULL; } }
打印的结果是

in add_element
element is  "password"
value is  "12345"
tagName is  "password"  element.text is  "12345"
password is  "12345"
element text is  "12345"
modify ok ! value is  "342345"
element text is  "342345"
modify ok ! value is  "1212342345"
ret02 is  false
element text is  "342345"
modify ok ! value is  "342345"
ret03 is  true

代码已经放到github上，另外，也放到了csdn资源上

https://github.com/buptis073114/XMLParseExample

QT中XML增删改查，不会有重复beta

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