xml文件读写

创建xml文件，对xml文件进行添加新节点、删除节点、更新节点。创建的如下的xml文件。

<?xml version="1.0" encoding="UTF-8"?>

-<FileItems>


-<FileInfo fileid="12jdkfjdkfkdfjkdfj">

<FileName>test.txt</FileName>

<last_seen>2014-06-09 10:30</last_seen>

<pushFileStaus>完成</pushFileStaus>

<ActionType>上传</ActionType>

<logFilePath>C: est.txt</logFilePath>

<SavedSize>1200</SavedSize>

<localFilePath>C: est.txt</localFilePath>

<HostIP>172.19.8.121</HostIP>

<Port>999</Port>

</FileInfo>

对xml文件进行查找，可以使用using System.Xml.Linq;命名空间中的XElement(XName)类，使用myXElement.Elements().Where(node => node.Attribute("fileid").Value == "12jdkfjdkfkdfjkdfj");其中myXElement是XElement的实例对象、fileid是xml节点属性名，“12jdkfjdkfkdfjkdfj”是属性的值。

/// <summary>
        /// MainWindow.xaml 的交互逻辑
        /// </summary>
        public partial class MainWindow : Window
        {
                public MainWindow()
                {
                        InitializeComponent();
                }
                string FullPath = string.Format(@"{0}{1}{2}", Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "FilePulla",  "history.xml");
                /// <summary>
                /// 创建xml文件
                /// </summary>
                /// <param name="sender"></param>
                /// <param name="e"></param>
                private void button1_Click(object sender, RoutedEventArgs e)
                { 
                       FileInfo xmlFile= new FileInfo(FullPath);
                       XmlTextWriter xmlWriter = new XmlTextWriter(xmlFile.FullName, Encoding.UTF8);
                       xmlWriter.WriteStartDocument();
                       xmlWriter.WriteStartElement("FileItems");

                       xmlWriter.WriteStartElement("FileInfo");
                       xmlWriter.WriteAttributeString("fileid", "12jdkfjdkfkdfjkdfj");
                       xmlWriter.WriteElementString("FileName", "test.txt");
                       xmlWriter.WriteElementString("last_seen", "2014-06-09 10:30");
                       xmlWriter.WriteElementString("pushFileStaus", "完成");
                       xmlWriter.WriteElementString("ActionType", "上传");
                       xmlWriter.WriteElementString("logFilePath", "C:	est.txt");
                       xmlWriter.WriteElementString("SavedSize", "1200");
                       xmlWriter.WriteElementString("localFilePath", "C:	est.txt");
                       xmlWriter.WriteElementString("HostIP", "172.19.8.121");
                       xmlWriter.WriteElementString("Port", "999");
                       xmlWriter.WriteEndElement();

                        ////////////////////////////////////////////////////////////////////
                       xmlWriter.WriteStartElement("FileInfo");
                       xmlWriter.WriteAttributeString("fileid", "12jdkfjdkfkdfjkdfj");
                       xmlWriter.WriteElementString("FileName", "test.txt");
                       xmlWriter.WriteElementString("last_seen", "2014-06-09 10:30");
                       xmlWriter.WriteElementString("pushFileStaus", "完成");
                       xmlWriter.WriteElementString("ActionType", "上传");
                       xmlWriter.WriteElementString("logFilePath", "C:	est.txt");
                       xmlWriter.WriteElementString("SavedSize", "1200");
                       xmlWriter.WriteElementString("localFilePath", "C:	est.txt");
                       xmlWriter.WriteElementString("HostIP", "172.19.8.121");
                       xmlWriter.WriteElementString("Port", "999");
                       xmlWriter.WriteEndElement();

                       xmlWriter.WriteFullEndElement();
                       xmlWriter.WriteEndDocument();
                       xmlWriter.Close();

                }
                /// <summary>
                /// 在已存在的文件上，添加新节点
                /// </summary>
                /// <param name="sender"></param>
                /// <param name="e"></param>
                private void button2_Click(object sender, RoutedEventArgs e)
                {
                        if (File.Exists(FullPath))
                        {
                                XmlDocument xmlDoc = new XmlDocument();
                                xmlDoc.Load(FullPath);
                                XmlNode root = xmlDoc.SelectSingleNode("FileItems");
                                //查找<bookstore>
                                XmlElement element = xmlDoc.CreateElement("FileInfo");
                                element.SetAttribute("fileid", "12jdkfjdkfkdfjkdfjere");

                                XmlElement xesub1 = xmlDoc.CreateElement("FileName");
                                xesub1.InnerText = "test.txt";
                                element.AppendChild(xesub1);
                                //设置文本节点
                                XmlElement xesub10 = xmlDoc.CreateElement("last_seen");
                                xesub10.InnerText = "2014-06-09 11:35";
                                element.AppendChild(xesub10);

                                XmlElement xesub2 = xmlDoc.CreateElement("pushFileStaus");
                                xesub2.InnerText = "test.txt";
                                element.AppendChild(xesub2);
                                XmlElement xesub3 = xmlDoc.CreateElement("ActionType");
                                xesub3.InnerText = "test.txt";
                                element.AppendChild(xesub3);
                                XmlElement xesub4 = xmlDoc.CreateElement("logFilePath");
                                xesub4.InnerText = "test.txt";
                                element.AppendChild(xesub4);
                                XmlElement xesub5 = xmlDoc.CreateElement("SavedSize");
                                xesub5.InnerText = "test.txt";
                                element.AppendChild(xesub5);
                                XmlElement xesub6 = xmlDoc.CreateElement("localFilePath");
                                xesub6.InnerText = "test.txt";
                                element.AppendChild(xesub6);
                                XmlElement xesub7 = xmlDoc.CreateElement("HostIP");
                                xesub7.InnerText = "test.txt";
                                element.AppendChild(xesub7);
                                XmlElement xesub8 = xmlDoc.CreateElement("HostIP");
                                xesub8.InnerText = "test.txt";
                                element.AppendChild(xesub8);
                                XmlElement xesub9 = xmlDoc.CreateElement("Port");
                                xesub9.InnerText = "test.txt";
                                element.AppendChild(xesub9);
                                root.AppendChild(element);
                                xmlDoc.Save(FullPath);
                        }
                      
                }
               /// <summary>
               /// 删除节点
               /// </summary>
               /// <param name="sender"></param>
               /// <param name="e"></param>
                private void button3_Click(object sender, RoutedEventArgs e)
                {
                        XElement xmlDoc = XElement.Load(FullPath);
                        XElement selectedElement = xmlDoc.Elements().Where(xl => xl.Attribute("fileid").Value == "12jdkfjdkfkdfjkdfjere").FirstOrDefault();
                        if (selectedElement == null) return;
                        selectedElement.Remove();
                        xmlDoc.Save(FullPath);
                }
                /// <summary>
                /// 修改节点的值
                /// </summary>
                /// <param name="sender"></param>
                /// <param name="e"></param>
                private void button5_Click(object sender, RoutedEventArgs e)
                {
                        XElement xmlDoc = XElement.Load(FullPath);
                        XElement selectedElement = xmlDoc.Elements().Where(xl => xl.Attribute("fileid").Value == "12jdkfjdkfkdfjkdfjere").FirstOrDefault();
                        if (selectedElement == null) return;
                        selectedElement.Elements("pushFileStaus").FirstOrDefault().SetValue("完成");
                        xmlDoc.Save(FullPath);
                }
        }