《Qt5：读写XML文件QXmlStreamWriter和QXmlStreamReader》_qt qmlstreamwrite写xml文件

Qt5读写XML文件需要用到QXmlStreamWriter类和QXmlStreamReader类。

QXmlStreamWriter类

The QXmlStreamWriter class provides an XML writer with a simple streaming API. 

Header:	#include <QXmlStreamWriter>
qmake:	QT += core
Since:	Qt 4.3

QXmlStreamReader类

The QXmlStreamReader class provides a fast parser for reading well-formed XML via a simple streaming API.

Header:	#include <QXmlStreamReader>
qmake:	QT += core
Since:	Qt 4.3

Qt帮助文档：

http://doc.qt.io/qt-5/qxmlstreamwriter.html 

http://doc.qt.io/qt-5/qxmlstreamreader.html

 读写XML

打开Qt，新建一个Qt Widgets Application项目，添加如下代码，文件保存路径需要自己稍作修改：

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
 
namespace Ui {
class MainWindow;
}
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
 
private:
    Ui::MainWindow *ui;
};
 
#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
//添加的头文件
#include "QXmlStreamWriter"//用于写入XML
#include "QXmlStreamReader"//用于读取XML
#include "QFile"//文件
#include "QDebug"//用于DEBUG输出
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    QFile file("C:\\Users\\dell\\Desktop\\Hello.xml");
    if (!file.open(QFile::ReadWrite|QIODevice::Truncate))
    {
        qDebug() << "Error: cannot open file";
    }
 
 
    QXmlStreamWriter stream(&file);
    stream.setAutoFormatting(true);
    stream.writeStartDocument();
 
    stream.writeStartElement("Information");
    stream.writeTextElement("Name", "可乐");
    stream.writeTextElement("Kind", "哈士奇");
    stream.writeTextElement("Sex", "女");
    stream.writeTextElement("BirthDay", "2018/10/22");
    stream.writeTextElement("Place","成都");
    stream.writeTextElement("Signature","我是一只快乐的小二哈，就是不拆家！");
    stream.writeStartElement("Other");
    stream.writeTextElement("Address","华润国际社区");
    stream.writeEndElement();
 
 
    stream.writeStartElement("Course");
    stream.writeTextElement("Chinese", "中文");
    stream.writeTextElement("English", "英文");
    stream.writeTextElement("Math", "数学");
    stream.writeTextElement("Music", "音乐");
    stream.writeEndElement();
    stream.writeEndElement();
 
    stream.writeEndDocument();
    file.close();
 
    qDebug() << "write finished!";
    if(file.open(QIODevice::ReadOnly | QIODevice::Text))
    {
 
        //构建QXmlStreamReader对象
        QXmlStreamReader reader(&file);
 
        while(!reader.atEnd())
        {
            //reader.readNext();//读取下一个开始元素
            reader.readNextStartElement();//读取下一个开始元素
            //判断是否是节点的开始
            if(reader.isStartElement())
            {
                QString strElementName = reader.name().toString();
                if (QString::compare(strElementName, "Information") == 0)
                {
                    qDebug() << QString::fromLocal8Bit("**********<Information>********** ");
                }
                else if (QString::compare(strElementName, QStringLiteral("Name")) == 0)
                {
                    qDebug() << QStringLiteral("Name：%1").arg(reader.readElementText());
                }
                else if (QString::compare(strElementName, QStringLiteral("Kind")) == 0)
                {  // 方式
                    qDebug() << QStringLiteral("Kind：%1").arg(reader.readElementText());
                }
                else if (QString::compare(strElementName, QStringLiteral("Sex")) == 0)
                {
                    qDebug() << QStringLiteral("Sex：%1").arg(reader.readElementText());
                }
                else if (QString::compare(strElementName, QStringLiteral("BirthDay")) == 0)
                {
                    qDebug() << QStringLiteral("BirthDay：%1").arg(reader.readElementText());
                }
                else if (QString::compare(strElementName, QStringLiteral("Place")) == 0)
                {
                    qDebug() << QStringLiteral("Place：%1").arg(reader.readElementText());
                }
                else if(QString::compare(strElementName, QStringLiteral("Signature")) == 0)
                {
                    qDebug() << QStringLiteral("Signature：%1").arg(reader.readElementText());
                }
                else if (QString::compare(strElementName, "Other") == 0)
                {
                    qDebug() << QString::fromLocal8Bit("**********<Other>********** ");
                    QString strName = reader.name().toString();//获取名字
                    qDebug() << QString("%1").arg(strName);
                    reader.readNext();//读取下一个开始元素
                }
                else if(QString::compare(strElementName, QStringLiteral("Address")) == 0)
                {
                    qDebug() << QStringLiteral("Address：%1").arg(reader.readElementText());
                    reader.readNextStartElement();//读取下一个开始元素
                }
                else if (QString::compare(strElementName, "Course") == 0)
                {
                    qDebug() << QString::fromLocal8Bit("**********<Course>********** ");
                    QString strName = reader.name().toString();//获取名字
                    qDebug() << QString("%1").arg(strName);
                }
                //reader.readNext();
                else if (QString::compare(strElementName, QStringLiteral("Chinese")) == 0)
                {  // 方式一
                    //判断是否是字符串
                    qDebug() << QStringLiteral("Chinese：%1").arg(reader.readElementText());
                }
                else if (QString::compare(strElementName, QStringLiteral("English")) == 0)
                {  // 方式
                    qDebug() << QStringLiteral("English：%1").arg(reader.readElementText());
                }
                else if (QString::compare(strElementName, QStringLiteral("Sex")) == 0)
                {
                    qDebug() << QStringLiteral("Sex：%1").arg(reader.readElementText());
                }
                else if (QString::compare(strElementName, QStringLiteral("Math")) == 0)
                {
                    qDebug() << QStringLiteral("Math：%1").arg(reader.readElementText());
                }
                else if(QString::compare(strElementName, QStringLiteral("Music")) == 0)
                {
                    qDebug() << QStringLiteral("Music：%1").arg(reader.readElementText());
                }
            }
 
        }
     file.close();
    }
    else
    {
        qDebug()<<"Open file hello.xml failure";
    }
}
 
MainWindow::~MainWindow()
{
    delete ui;
}

写入效果

<?xml version="1.0" encoding="UTF-8"?>
<Information>
    <Name>可乐</Name>
    <Kind>哈士奇</Kind>
    <Sex>女</Sex>
    <BirthDay>2018/10/22</BirthDay>
    <Place>成都</Place>
    <Signature>我是一只快乐的小二哈，就是不拆家！</Signature>
    <Other>
        <Address>华润国际社区</Address>
    </Other>
    <Course>
        <Chinese>中文</Chinese>
        <English>英文</English>
        <Math>数学</Math>
        <Music>音乐</Music>
    </Course>
</Information>

读取效果

write finished!
"**********<Information>********** "
"Name：可乐"
"Kind：哈士奇"
"Sex：女"
"BirthDay：2018/10/22"
"Place：成都"
"Signature：我是一只快乐的小二哈，就是不拆家！"
"**********<Other>********** "
"Other"
"Address：华润国际社区"
"**********<Course>********** "
"Course"
"Chinese：中文"
"English：英文"
"Math：数学"
"Music：音乐"

完整代码

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