TreeNode.ValuePath 属性

定义

获取从根节点到当前节点的路径。Gets the path from the root node to the current node.

public:
 property System::String ^ ValuePath { System::String ^ get(); };
[System.ComponentModel.Browsable(false)]
public string ValuePath { get; }
[<System.ComponentModel.Browsable(false)>]
member this.ValuePath : string
Public ReadOnly Property ValuePath As String

属性值

String

由分隔符分隔的节点值列表,这些值构成从根节点到当前节点的路径。A delimiter-separated list of node values that form a path from the root node to the current node.

属性

示例

下面的代码示例演示如何分析 ValuePath 属性。The following code example demonstrates how to parse the ValuePath property.


<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void Index_Changed(Object sender, EventArgs e)
  {

    // Set the PathSeparator character based on the user's selection.
    // Notice that the value must be converted to a Char data type.
    BookTreeView.PathSeparator = Convert.ToChar(List.SelectedItem.Text);

    // Display the ValuePath values for the second-level nodes.
    Message.Text = "The ValuePath values for the second-level nodes are:<br />";
    foreach(TreeNode node in BookTreeView.Nodes[0].ChildNodes)
    {

      // Create the delimiter array with the PathSeparator value for the Split method.
      Char[] DelimiterArray = new Char[1];
      DelimiterArray[0] = BookTreeView.PathSeparator;

      // Parse the ValuePath value using the delimiter array.
      String[] NodeValues = node.ValuePath.Split(DelimiterArray);

      // Display the node values.
      for(int i=0; i<NodeValues.Length; i++)
      {
        if(i != NodeValues.Length - 1)
        {   
          // Append the delimiter character.
          Message.Text += NodeValues[i] + BookTreeView.PathSeparator.ToString();
        }
        else
        {
          // Do not append the delimiter character.
          Message.Text += NodeValues[i];
        }

      }

      // Append a line break for the next node.
      Message.Text += "<br />";

    }

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >

  <head runat="server">
    <title>TreeView PathSeparator Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>TreeView PathSeparator Example</h3>
      
      <asp:TreeView id="BookTreeView"
        ExpandDepth="-1"
        PathSeparator="/"
        runat="server">
         
        <Nodes>
        
          <asp:TreeNode Value="Chapter 1" 
            Text="Chapter 1">
             
            <asp:TreeNode Value="Section 1"
              Text="Section 1">
               
              <asp:TreeNode Value="Paragraph 1" 
                Text="Paragraph 1">
              </asp:TreeNode>
                
            </asp:TreeNode>
            
            <asp:TreeNode Value="Section 2" 
              Text="Section 2">
            </asp:TreeNode>
            
          </asp:TreeNode>
        
        </Nodes>
        
      </asp:TreeView>
      
      <br />
      
      <asp:Label id="Message" runat="server"/>
      
      <hr />
      
      Select a path separator value:<br />
      
      <asp:DropDownList ID="List"
        AutoPostBack="true"
        OnSelectedIndexChanged="Index_Changed"   
        runat="server">
      
        <asp:ListItem Selected="true">/</asp:ListItem>
        <asp:ListItem>\</asp:ListItem>
        <asp:ListItem>|</asp:ListItem>
        <asp:ListItem>,</asp:ListItem>
        <asp:ListItem>;</asp:ListItem>
      
      </asp:DropDownList>

    </form>
  </body>
</html>


<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Sub Index_Changed(ByVal sender As Object, ByVal e As EventArgs)

    ' Set the PathSeparator character based on the user's selection.
    ' Notice that the value must be converted to a Char data type.
    BookTreeView.PathSeparator = Convert.ToChar(List.SelectedItem.Text)

    ' Display the ValuePath values for the second-level nodes.
    Message.Text = "The ValuePath values for the second-level nodes are:<br />"
    Dim node As TreeNode
    For Each node In BookTreeView.Nodes(0).ChildNodes

      ' Create the delimiter array with the PathSeparator value for the Split method.
      Dim DelimiterArray(1) As Char
      DelimiterArray(0) = BookTreeView.PathSeparator

      ' Parse the ValuePath value using the delimiter array.
      Dim NodeValues() As String = node.ValuePath.Split(DelimiterArray)

      ' Display the node values.
      Dim i As Integer

      For i = 0 To NodeValues.Length - 1

        If i <> NodeValues.Length - 1 Then

          ' Append the delimiter character.
          Message.Text &= NodeValues(i) & BookTreeView.PathSeparator.ToString()

        Else

          ' Do not append the delimiter character.
          Message.Text &= NodeValues(i)

        End If

      Next

      ' Append a line break for the next node.
      Message.Text &= "<br />"

    Next

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >

  <head runat="server">
    <title>TreeView PathSeparator Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>TreeView PathSeparator Example</h3>
      
      <asp:TreeView id="BookTreeView"
        ExpandDepth="-1"
        PathSeparator="/"
        runat="server">
         
        <Nodes>
        
          <asp:TreeNode Value="Chapter 1" 
            Text="Chapter 1">
             
            <asp:TreeNode Value="Section 1"
              Text="Section 1">
               
              <asp:TreeNode Value="Paragraph 1" 
                Text="Paragraph 1">
              </asp:TreeNode>
                
            </asp:TreeNode>
            
            <asp:TreeNode Value="Section 2" 
              Text="Section 2">
            </asp:TreeNode>
            
          </asp:TreeNode>
        
        </Nodes>
        
      </asp:TreeView>
      
      <br />
      
      <asp:Label id="Message" runat="server"/>
      
      <hr />
      
      Select a path separator value:<br />
      
      <asp:DropDownList ID="List"
        AutoPostBack="true"
        OnSelectedIndexChanged="Index_Changed"   
        runat="server">
      
        <asp:ListItem Selected="true">/</asp:ListItem>
        <asp:ListItem>\</asp:ListItem>
        <asp:ListItem>|</asp:ListItem>
        <asp:ListItem>,</asp:ListItem>
        <asp:ListItem>;</asp:ListItem>
      
      </asp:DropDownList>

    </form>
  </body>
</html>

注解

ValuePath属性包含以分隔符分隔的节点值列表,这些值构成从根节点到当前节点的路径。The ValuePath property contains a delimiter-separated list of node values that form a path from the root node to the current node. 使用 PathSeparator 属性指定分隔节点值时所用的分隔符字符。Use the PathSeparator property to specify the delimiter character used to separate the node values. 此值通常在分析各个值的列表时使用,或者作为参数传递给 FindNode 类的方法 TreeViewThis value is commonly used when parsing the list for the individual values, or to pass as an argument to the FindNode method of the TreeView class.

根据控件中显示的值 TreeView ,分隔符字符可能需要更改以防止任何冲突。Depending on the value displayed in the TreeView control, the delimiter character might need to be changed to prevent any conflicts. 例如,如果将分隔符字符设置为逗号,则显示的值不应包含任何逗号;否则,将无法准确分析 ValuePath 属性。For example, if you set the delimiter character to a comma, the displayed value should not contain any commas; otherwise, you cannot accurately parse the ValuePath property.

备注

对于同一级别的节点,每个节点都必须具有唯一的 Value 属性值; TreeView 控件不能区分同一级别上具有相同值的不同节点。Nodes at the same level must each have a unique value for the Value property; the TreeView control cannot distinguish between different nodes at the same level that have the same value. 在这种情况下,如果用户单击具有重复值的节点,则会选择该控件中的第一个节点 TreeViewIn this scenario, if the user clicks a node that has a duplicate value, the node that appears first in the TreeView control is selected.

适用于

另请参阅