xmlnode 的value与innertext区别

1。当node是叶子节点时

        XmlDocument doc = new XmlDocument();

        doc.LoadXml("<right>a</right>");

        XmlNode root = doc.DocumentElement;
        Console.WriteLine(root.InnerText);

结果是：a

 

2。当node是父节点时，将包括子节点的所有的innertext显示出来

        XmlDocument doc = new XmlDocument();

        doc.LoadXml("<root name=‘jack‘ value = ‘jacky‘ ><right>a</right><left>b</left>content</root>");

        XmlNode root = doc.DocumentElement;
        Console.WriteLine(root.InnerText);

结果是：abcontent

 

3。显示属性值

   如果想显示root的name属性值，可以通过innertext和value获得

         XmlDocument doc = new XmlDocument();

        doc.LoadXml("<root name=‘jack‘ value = ‘jacky‘ ><right id =‘007‘>a</right><left>b</left>content</root>");

        XmlNode root = doc.DocumentElement;
        XmlNode node = root.SelectSingleNode("right");

        Console.WriteLine(node.Attributes["id"].InnerText);
        Console.WriteLine(node.Attributes["id"].Value);

 

或者 XmlNode root = doc.DocumentElement;
        XmlNode node = root.SelectSingleNode("right");
         node = node.SelectSingleNode("@id");

        Console.WriteLine(node.InnerText);
        Console.WriteLine(node.Value);

 

4。当取节点的Value时，我们发现为空

        XmlNode root = doc.DocumentElement;
        XmlNode node = root.SelectSingleNode("right");

        Console.WriteLine(node.Value);//rerult is  null reference
        Console.WriteLine(node.InnerText);// result is a

 原因是：

value这个属性比较特殊，它返回的值与当前节点的nodetype有关：（MSDN）

Type	Value
Attribute	The value of the attribute.
CDATASection	The content of the CDATA Section.
Comment	The content of the comment.
Document	a null reference (Nothing in Visual Basic).
DocumentFragment	a null reference (Nothing in Visual Basic).
DocumentType	a null reference (Nothing in Visual Basic).
Element	a null reference (Nothing in Visual Basic). You can use the XmlElement.InnerText or XmlElement.InnerXml properties to access the value of the element node.
Entity	a null reference (Nothing in Visual Basic).
EntityReference	a null reference (Nothing in Visual Basic).
Notation	a null reference (Nothing in Visual Basic).
ProcessingInstruction	The entire content excluding the target.
Text	The content of the text node.

 

例4中node的nodetype是element，所以通过value返回值是空引用，而当我们取得属性的value时，因为它的nodetype为attribute，他返回是属性的值