如何在vb.net中更新多个子节点 [英] how to Update more then one child nodes in vb.net

问题描述

预先感谢，什么是更新一个节点的一个以上子节点的正确方法，这是我的XML文档

Thanks in advance , what is the correct way to update more then one child nodes of a node , Here is my XML document

<?xml version="1.0"?>
<Names>
  <Name>
    <First_Name>FN 1</First_Name>
    <Middle_Name>MN 1</Middle_Name>
    <Last_Name>LN 1</Last_Name>
    <Country_Code>001</Country_Code>
    <Area_Code>
    </Area_Code>
    <Phone_No>
    </Phone_No>
    <Email_Address>[e-mail]</Email_Address>
    <Address>Address 1</Address>
  </Name>
  <Name ID="2">
    <First_Name>FN2</First_Name>
    <Middle_Name>Mn2</Middle_Name>
    <Last_Name>Ln2</Last_Name>
    <Country_Code>02</Country_Code>
    <Area_Code>002</Area_Code>
    <Phone_No>0002</Phone_No>
    <Email_Address>[e-mail]</Email_Address>
    <Address>
    </Address>
  </Name>
  </Names>

我能够更新第一个子节点，但在第二个子节点上却给出错误''对象引用未设置为对象的实例.i
想要实现的是更新所有子节点，欢迎任何形式的帮助

I am able to update 1st child node but on second child node it gives error '' "Object reference not set to an instance of an object. what i
want to achieve is to update all the child nodes, any kind of help will be welcomed

Function Edit() As Boolean
        Try
            ''Dim xd As New XmlDocument()
            ''xd.Load(App_Path)
            ''Dim nod As XmlNodeList = xd.SelectNodes("//First_Name[. = ''" & txtFName.Text & "'']" & "/parent::node()/First_Name")

            ''If nod IsNot Nothing Then
            ''    For Each node In nod
            ''        ''nod.Item(0).ChildNodes(0).InnerText = txtMName.Text.Trim
            ''        ''nod.Item(0).ChildNodes(1).InnerText = txtLName.Text.Trim
            ''    Next

            ''End If

            Dim xd As New XmlDocument()
            xd.Load(App_Path)
            Dim nod As XmlNode = xd.SelectSingleNode("//First_Name[. = ''" & txtFName.Text & "'']" & "/parent::node()/First_Name")
            If nod IsNot Nothing Then
                nod.ChildNodes(0).InnerText = "33"
                nod.ChildNodes(1).InnerText = "333"
            End If

            Edit = True
        Catch ex As Exception

            MessageBox.Show(ex.Message)
            ctlStatus.Text = "Current State : " & ex.Message.ToString
            Return False
        End Try
        Return Edit
    End Function

推荐答案

您显示的两个节点都有不同的First_Name值.您的SelectSingleNode正在寻找一个特定的节点，因此您在集合中当然只有一个节点.

如果可以，则应使用Linq to XML.它使遍历和操作XML非常容易.

Both nodes you have displayed have different First_Name values. Your SelectSingleNode is looking for a specific node so of course you only have one node in the collection.

If you can, you should use Linq to XML. It makes traversing and manipulating XML very easy.

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