VB.NET中操作xml文件

已知有一个XML文件（bookstore.xml）如下：

<?
xml version="1.0" encoding="gb2312"
?>

<
bookstore
>

<
book
genre
="fantasy"
ISBN
="2-3631-4"
>

<
title
>
Oberon's Legacy
</
title
>

<
author
>
Corets, Eva
</
author
>

<
price
>
5.95
</
price
>

</
book
>

</
bookstore
>

往<bookstore>节点中插入一个<book>节点：

Dim
xmlDoc
As

New
XmlDocument()

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
"
)

结果为：

<?
xml version="1.0" encoding="gb2312"
?>

<
bookstore
>

<
book
genre
="fantasy"
ISBN
="2-3631-4"
>

<
title
>
Oberon's Legacy
</
title
>

<
author
>
Corets, Eva
</
author
>

<
price
>
5.95
</
price
>

</
book
>

<
book
genre
="李赞红"
ISBN
="2-3631-4"
>

<
title
>
CS从入门到精通
</
title
>

<
author
>
候捷
</
author
>

<
price
>
58.3
</
price
>

</
book
>

</
bookstore
>

修改节点：将genre属性值为“李赞红“的节点的genre值改为“update李赞红”，将该节点的子节点<author>的文本修改为 “亚胜”。

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
ForEach
'
找到退出来就可以了

End

If

Next
xn1

Exit
ForEach

End

If

Next
xn

显示所有数据。

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