xml操作总结

 1. Document有两个子节点，xml头描述节点和book节点。book节点是top level点节点，可以通过DocumentElement属性得到。是能有一个top level element节点。Only one top level element is allowed in an XML document.

<?xml version="1.0" encoding="gb2312"?>
<book genre="novel" ISBN="1-861001-57-5">
  <Appearance>
    <ColumnHeaderCell>
      <Interior>Solid; 181, 206, 251</Interior>
      <Font>
        <Bold>true</Bold>
      </Font>
    </ColumnHeaderCell>
  </Appearance>
  <title>Pride And Prejudice</title>
  <price>19.95</price>
  <Appearance>
    <ColumnHeaderCell>
      <Interior>Solid; 181, 206, 251</Interior>
      <Font>
        <Bold>true</Bold>
      </Font>
    </ColumnHeaderCell>
  </Appearance>
</book>

Element是Node的子集，XmlNode表示一个节点，包括XmlElement(元素)和XmlAttribute(属性)等。 如：

<Alarm lock="true">             //node   
      <Time>                       //node   
          StringValue              //node   
      </Time>                      //node   
</Alarm>                           //node  

  以上Alarm(元素节点),lock(属性节点),Time(元素节点),StringValue(文本节点)都是Node，但是只有 <Alarm>......</Alarm>和<Time>StringValue</Time>是Element  

XmlNode: 属性节点()、注释节点、文本节点（XmlText）、元素节点(XmlElement)等。

System.Xml.XmlDeclaration 表示 XML 声明节点：<?xml version='1.0'...?>。

    // Summary:
    //     Specifies the type of node.
    public enum XmlNodeType
    {
        // Summary:
        //     This is returned by the System.Xml.XmlReader if a Read method has not been
        //     called.
        None = 0,
        //
        // Summary:
        //     An element (for example, <item> ).
        Element = 1,
        //
        // Summary:
        //     An attribute (for example, id='123' ).
        Attribute = 2,
        //
        // Summary:
        //     The text content of a node.
        Text = 3,
        //
        // Summary:
        //     A CDATA section (for example, <![CDATA[my escaped text]]> ).
        CDATA = 4,
        //
        // Summary:
        //     A reference to an entity (for example, &num; ).
        EntityReference = 5,
        //
        // Summary:
        //     An entity declaration (for example, <!ENTITY...> ).
        Entity = 6,
        //
        // Summary:
        //     A processing instruction (for example, <?pi test?> ).
        ProcessingInstruction = 7,
        //
        // Summary:
        //     A comment (for example, <!-- my comment --> ).
        Comment = 8,
        //
        // Summary:
        //     A document object that, as the root of the document tree, provides access
        //     to the entire XML document.
        Document = 9,
        //
        // Summary:
        //     The document type declaration, indicated by the following tag (for example,
        //     <!DOCTYPE...> ).
        DocumentType = 10,
        //
        // Summary:
        //     A document fragment.
        DocumentFragment = 11,
        //
        // Summary:
        //     A notation in the document type declaration (for example, <!NOTATION...>
        //     ).
        Notation = 12,
        //
        // Summary:
        //     White space between markup.
        Whitespace = 13,
        //
        // Summary:
        //     White space between markup in a mixed content model or white space within
        //     the xml:space="preserve" scope.
        SignificantWhitespace = 14,
        //
        // Summary:
        //     An end element tag (for example, </item> ).
        EndElement = 15,
        //
        // Summary:
        //     Returned when XmlReader gets to the end of the entity replacement as a result
        //     of a call to System.Xml.XmlReader.ResolveEntity().
        EndEntity = 16,
        //
        // Summary:
        //     The XML declaration (for example, <?xml version='1.0'?> ).
        XmlDeclaration = 17,
    }

插入一段xml格式文本到原xml。

1. 创建XmlDocument，载入xml片段，导入原XmlDocument得到XmlNode，最后插入这个节点。

        static void Testcase3()
        {
            XmlDocument doc0 = new XmlDocument();
            doc0.Load("data.xml");

            XmlDocument doc = new XmlDocument();
            doc.LoadXml("<book genre='novel' ISBN='1-861001-57-5'>" +
                        "<title>Pride And Prejudice</title>" +
                        "</book>");

            XmlDocument doc2 = new XmlDocument();
            doc2.LoadXml("<Appearance><ColumnHeaderCell><Interior>Solid; 181, 206, 251</Interior><Font><Bold>true</Bold></Font></ColumnHeaderCell></Appearance>");
            XmlNode nodeInsert2 = doc.ImportNode(doc2.DocumentElement, true);

            XmlDocument doc3 = new XmlDocument();
            doc3.LoadXml("<Appearance><ColumnHeaderCell><Interior>Solid; 181, 206, 251</Interior><Font><Bold>true</Bold></Font></ColumnHeaderCell></Appearance>");
            XmlNode nodeInsert3 = doc.ImportNode(doc2.DocumentElement, true);

            XmlNode root = doc.DocumentElement;

            //Create a new node.
            XmlElement elem = doc.CreateElement("price");
            elem.InnerText = "19.95";

            //Add the node to the document.
            root.InsertAfter(elem, root.FirstChild);
            root.AppendChild(nodeInsert2);
            root.InsertBefore(nodeInsert3, root.FirstChild);

            Console.WriteLine("Display the modified XML...");
            doc.Save(Console.Out);

            Console.WriteLine();
        }

2. 使用XmlDocumentFragment，省去了ImportNode的过程。

static void StepOne(string fileName)
        {
            // original xml document
            XmlDocument docMain = new XmlDocument();
            docMain.Load(fileName);

            // Create the XmlDocument.
            XmlDocumentFragment docFrag = docMain.CreateDocumentFragment();
            docFrag.InnerXml = "<Appearance><ColumnHeaderCell><Interior>Solid; 181, 206, 251</Interior><Font><Bold>true</Bold></Font></ColumnHeaderCell></Appearance>";

            XmlDocumentFragment docFrag2 = docMain.CreateDocumentFragment();
            docFrag2.InnerXml = "<Appearance><ColumnHeaderCell><Interior>Solid; 181, 206, 251</Interior><Font><Bold>true</Bold></Font></ColumnHeaderCell></Appearance>";

            // Create a new element and add it to the document.
            XmlNode nodeGridGridEngine = docMain["Grid"]["GridSchema"]["GridEngine"];
            XmlNode nodeTableDescriptor = nodeGridGridEngine["TableDescriptor"];
            nodeGridGridEngine.InsertAfter(docFrag, nodeTableDescriptor);

            //GridGroupingLookAndFeel, TableOptions, 
            XmlNode nodeGridGroupingLookAndFeel = docMain["Grid"]["GridGroupingLookAndFeel"];
            XmlNode nodeTableOptions = nodeGridGroupingLookAndFeel["TableOptions"];
            nodeGridGroupingLookAndFeel.InsertAfter(docFrag2, nodeTableOptions);

            docMain.Save(fileName);
        }