XML學習筆記(七)：XPath資料模式

• XPath資料模式依賴存System.Xml.XPath命名空間的XPathNavigator類。
• XPathNavigator類是一個抽象類別，是一個以指標方式為基礎的瀏覽XML資料的模式，它允許你對XML檔案進行編輯。
• 你可以從任何實現了IXPathNavigable介面的類獲得XPathNavigator類的一個執行個體。XmlDocument和XPathDocument就是實現了這個介面的類。
• XmlDocument返回的XML是可編輯的，XPathDocument返回對象是唯讀。

建立XPathNavigator對象：

 

   1:    //功能性範例程式碼：

   2:  private void button1_Click(object sender, EventArgs e)

   3:      {

   4:          XPathNavigator navigator = null;

   5:          if (radioButton1.Checked)

   6:          {

   7:              //XmlDocument類建立XPathNavigator對象

   8:              XmlDocument doc = new XmlDocument();

   9:              doc.Load(Application.StartupPath + @"/employees.xml");

  10:              navigator = doc.CreateNavigator();

  11:          }

  12:          else

  13:          {

  14:              //XmlPathDocument類建立XPathNavigator對象

  15:              XPathDocument doc = new XPathDocument(Application.StartupPath + @"/employees.xml");

  16:              navigator = doc.CreateNavigator();

  17:          }

  18:          MessageBox.Show("Navigator created successfully!");

  19:      }

通過XPathNavigator來瀏覽XML文檔

 

   1:   protected void Button1_Click(object sender, EventArgs e)

   2:      {

   3:          XPathDocument doc =new XPathDocument(xmlFilePath);

   4:          XPathNavigator navigator = doc.CreateNavigator();

   5:          navigator.MoveToRoot();

   6:          navigator.MoveToFirstChild();        

   7:          TreeNode root = TreeView1.Nodes.Add("Employees");

   8:          while (navigator.MoveToNext())

   9:          {

  10:              if (navigator.HasChildren)

  11:              {

  12:                  navigator.MoveToFirstChild();

  13:                  do

  14:                  {

  15:                      string id = navigator.GetAttribute("employeeid", "");

  16:                      TreeNode empnode = new TreeNode("Employee ID :" + id);

  17:                      root.Nodes.Add(empnode);

  18:                      navigator.MoveToFirstChild();

  19:                      do

  20:                      {

  21:                          string name = navigator.Name;

  22:                          TreeNode node = new TreeNode(name + " : " + navigator.Value);

  23:                          empnode.Nodes.Add(node);

  24:                      } while (navigator.MoveToNext());

  25:                      navigator.MoveToParent();

  26:                  }

  27:                  while (navigator.MoveToNext());

  28:              }

  29:          }

  30:      }

參考書籍

XSLT 2.0 and XPath 2.0 Programmer's Reference (Programmer to Programmer)