vb.net 操作xml

xml文件：

<?xml version="1.0" encoding="gb2312"?><bookstore>  <book ISBN="2-3631-4">    <title>Oberon's   Legacy</title>    <author>Corets,   Eva</author>    <price>5.95</price>  </book></bookstore>

code：

Imports System.XmlPublic Class Form1    Dim xmlDoc As New XmlDocument()    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click        '往<bookstore>节点中插入一个<book>节点：        xmlDoc.Load("bookstore.xml")        Dim root As XmlNode = xmlDoc.SelectSingleNode("bookstore") '查找<bookstore>          Dim xe1 As XmlElement = xmlDoc.CreateElement("book") '创建一个<book>节点          xe1.SetAttribute("genre", "李赞红") '设置该节点genre属性          xe1.SetAttribute("ISBN", "2-3631-4") '设置该节点ISBN属性          Dim xesub1 As XmlElement = xmlDoc.CreateElement("title")        xesub1.InnerText = "CS从入门到精通" '设置文本节点          xe1.AppendChild(xesub1) '添加到<book>节点中          Dim xesub2 As XmlElement = xmlDoc.CreateElement("author")        xesub2.InnerText = "候捷"        xe1.AppendChild(xesub2)        Dim xesub3 As XmlElement = xmlDoc.CreateElement("price")        xesub3.InnerText = "58.3"        xe1.AppendChild(xesub3)        root.AppendChild(xe1) '添加到<bookstore>节点中          xmlDoc.Save("bookstore.xml")    End Sub    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click        Dim nodeList As XmlNodeList = xmlDoc.SelectSingleNode("bookstore").ChildNodes '获取bookstore节点的所有子节点          Dim xn As XmlNode        For Each xn In nodeList '遍历所有子节点              Dim xe As XmlElement = CType(xn, XmlElement) '将子节点类型转换为XmlElement类型              If xe.GetAttribute("genre") = "李赞红" Then '如果genre属性值为“李赞红”                  xe.SetAttribute("genre", "update李赞红") '则修改该属性为“update李赞红”                  Dim nls As XmlNodeList = xe.ChildNodes '继续获取xe子节点的所有子节点                  Dim xn1 As XmlNode                For Each xn1 In nls '遍历                      Dim xe2 As XmlElement = CType(xn1, XmlElement) '转换类型                      If xe2.Name = "author" Then '如果找到                          xe2.InnerText = "亚胜" '则修改                          Exit For '找到退出来就可以了                      End If                Next xn1                Exit For            End If        Next xn        xmlDoc.Save("bookstore.xml") '保存。    End Sub    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click        Dim xnl As XmlNodeList = xmlDoc.SelectSingleNode("bookstore").ChildNodes        Dim xn As XmlNode        For Each xn In xnl            Dim xe As XmlElement = CType(xn, XmlElement)            If xe.GetAttribute("genre") = "fantasy" Then                xe.RemoveAttribute("genre") '删除genre属性              Else                If xe.GetAttribute("genre") = "update李赞红" Then                    xe.RemoveAll() '删除该节点的全部内容                  End If            End If        Next xn        xmlDoc.Save("bookstore.xml")    End Sub    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click        Dim xn As XmlNode = xmlDoc.SelectSingleNode("bookstore")        Dim xnl As XmlNodeList = xn.ChildNodes        Dim xnf As XmlNode        For Each xnf In xnl            Dim xe As XmlElement = CType(xnf, XmlElement)            Console.WriteLine(xe.GetAttribute("genre")) '显示属性值              Console.WriteLine(xe.GetAttribute("ISBN"))            Dim xnf1 As XmlNodeList = xe.ChildNodes            Dim xn2 As XmlNode            For Each xn2 In xnf1                Console.WriteLine(xn2.InnerText) '显示子节点点文本              Next xn2        Next xnf    End SubEnd Class