命名空间：
System.Xml.Linq
一、Linq读取XML
1、demo.xml
<?xml version="1.0" encoding="utf-8" ?>
<note>
<conf>
<to>infozero</to>
<from>lerroy</from>
<heading>测试信息</heading>
<body>第一条测试信息</body>
<title name="我的第一条消息">from myself</title>
</conf>
<conf>
<to>infozero@163.com</to>
<from>text</from>
<heading> 时刻提醒我 </heading>
<body>这是一条测试信息！</body>
<title name="我的第二条消息">from others</title>
</conf>
</note>
2、读取XML
XDocument doc = XDocument.Load(System.Web.HttpContext.Current.Server.MapPath("demo.xml"));
var text = from t in doc.Descendants("conf")
.Where(w => w.Element("to").Value.Contains('@'))
select new
{
to = t.Element("to").Value,froms = t.Element("from").Value,body = t.Element("body").Value
};
foreach (var a in text)
{
Response.Write(a.to+a.froms+a.body);
}
二、加载和解析XML内容
string myElement = @"<Car id='3'>
<Color>Yellow</Color>
<Make>Yugo</Make>
</Car>";
XElement newElemment = XElement.Parse(myElement);
newElemment.Save(System.Web.HttpContext.Current.Server.MapPath("demo1.xml"));
newElemment.Descendants("Color").Remove();//查询Color元素，并删除
newElemment.Descendants("Color").First().Value; //获取节点的值
三、XElement、XDocument 创建XML文档
//1、 XElement 创建XML文档
XElement doc = new XElement("ProductsParameter",new XAttribute("ID","1000"),new XElement("Products",new XElement("PoductType","DTSD342-9N"),new XElement("Queries","00020004")),new XElement("Variable",new XElement("Ua",new XElement("ID","1"),new XElement("Name","Ua"),new XElement("Description","A相电压"),new XElement("VType","DL/T 645-1997"),new XElement("Link","DL_0_0_DCBA"),new XElement("Formula","2#主变_DLT97_380.Ua}*{2#主变_DLT97_380.PTRatio}/10000"),new XElement("Unit","kv"),new XElement("Digit","3"),new XElement("ZeroFloat","0"),new XElement("InitValue",new XElement("MaxValue","10000000000"),new XElement("MinValue","-10000000000"),new XElement("IsRecord","True"),new XElement("RecordCycle","300"),new XElement("IsBroken","False")
))
);
string path = Environment.CurrentDirectory;
doc.Save(string.Format(@"{0}\ProductsXML\DTSD342-9N.xml",path));
//2、XDocument 创建XML文档
XDocument Xdoc = new XDocument(
//XDeclaration 指定版本，编码
new XDeclaration("1.0","utf-8","yes"),new XComment("注释！"),//XProcessingInstruction XML处理指令
new XProcessingInstruction("xml-stylesheet","href='MyStyles.css' title='Compact' type='text/css'"),new XElement("Inventory",new XElement("Car",1),new XElement("Color","Green"),new XElement("Make","BMW")
),2),"Red"),"yugo"))
)
);
Xdoc.Save(string.Format(@"{0}\ProductsXML\Inventory.xml",path));
生成XML文件
<?xml version="1.0" encoding="utf-8"?>
<ProductsParameter ID="1000">
<Products>
<PoductType>DTSD342-9N</PoductType>
<Queries>00020004</Queries>
</Products>
<Variable>
<Ua>
<ID>1</ID>
<Name>Ua</Name>
<Description>A相电压</Description>
<VType>DL/T 645-1997</VType>
<Link>DL_0_0_DCBA</Link>
<Formula>2#主变_DLT97_380.Ua}*{2#主变_DLT97_380.PTRatio}/10000</Formula>
<Unit>kv</Unit>
<Digit>3</Digit>
<ZeroFloat>0</ZeroFloat>
<InitValue>0</InitValue>
<MaxValue>10000000000</MaxValue>
<MinValue>-10000000000</MinValue>
<IsRecord>True</IsRecord>
<RecordCycle>300</RecordCycle>
<IsBroken>False</IsBroken>
</Ua>
</Variable>
</ProductsParameter>
<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<!--注释！-->
<?xml-stylesheet href='MyStyles.css' title='Compact' type='text/css'?>
<Inventory>
<Car ID="1">
<Color>Green</Color>
<Make>BMW</Make>
</Car>
<Car ID="2">
<Color>Red</Color>
<Make>yugo</Make>
</Car>
</Inventory>
XDocument 与XElement 区别？
二者在通过Load方法加载XML时，你会发现二者的区别：
简单概括就是：
XDocument.Load() 加载整个XML文档 包括根节点
XElement.Load()不会加载XML的根节点
XElement.Load()示例代码：
File.WriteAllText("Test.xml",@"<Root>
<Child1>1</Child1>
<Child2>2</Child2>
<Child3>3</Child3>
</Root>");
Console.WriteLine("Querying tree loaded with XElement.Load");
Console.WriteLine("----");
XElement doc = XElement.Load("Test.xml");
IEnumerable<XElement> childList =
from el in doc.Elements()
select el;
foreach (XElement e in childList)
Console.WriteLine(e);
结果：
Querying tree loaded with XElement.Load ---- <Child1>1</Child1> <Child2>2</Child2> <Child3>3</Child3>
XDocument.Load() 示例代码：
File.WriteAllText("Test.xml",@"<Root>
<Child1>1</Child1>
<Child2>2</Child2>
<Child3>3</Child3>
</Root>");
Console.WriteLine("Querying tree loaded with XDocument.Load");
Console.WriteLine("----");
XDocument doc = XDocument.Load("Test.xml");
IEnumerable<XElement> childList =
from el in doc.Elements()
select el;
foreach (XElement e in childList)
Console.WriteLine(e);
结果：
Querying tree loaded with XDocument.Load ---- <Root> <Child1>1</Child1> <Child2>2</Child2> <Child3>3</Child3> </Root>
四、将数组、ADO.NET、文件数据转换成XML
1、数组
//数组转换成XML
static void MakeXElementFromArray()
{
var people = new[] {
new {FirstName="张三",Age=20},new {FirstName="李四",Age=20}
};
var arrayDataAsXElement = from c in people
select
new XElement("Person",new XAttribute("Age",c.Age),new XElement("FirstName",c.FirstName));
XElement peopleDoc = new XElement("People",arrayDataAsXElement);
Console.Write(peopleDoc);
}
效果：
<People>
<Person Age="20">
<FirstName>张三</FirstName>
</Person>
<Person Age="20">
<FirstName>李四</FirstName>
</Person>
</People>