Question

请教VBnet的“未将对象引用设置到对象的实例”

如下例：
Dim xmlDoc As New Xml.XmlDocument
xmlDoc.Load("c:\program files\wtsystem\config.xml")

Dim myPcAdress As String
myPcAdress = xmlDoc.SelectSingleNode("configuration")_
.SelectSingleNode("equipment")_
.SelectSingleNode("myComputer")_
.SelectSingleNode("adress")_
.InnerText

例子中最后一句，报错提示“未将对象引用设置到对象的实例”，该怎么改呢？菜鸟求助于高手！

Answer 1

　　SelectSingleNode 的用法如下

Module Module1

    Sub Main()
        Dim xmlDoc As New Xml.XmlDocument
        xmlDoc.Load("c:\program files\wtsystem\config.xml")

        Dim myPcAdress As String
        myPcAdress = xmlDoc.SelectSingleNode("/configuration/equipment/myComputer/adress") _
                     .InnerText

    End Sub

End Module

Answer 2

某一个节点不存在，导致SelectSingleNode查找的结果是空的
这么改
var node = xmlDoc.SelectSingleNode("configuration/equipment/myComputer/adress")

如果node不为nothing 则
myPcAdress = node.InnerText