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MenuItem.Depth Proprietà

Definizione

Ottiene il livello in cui viene visualizzata una voce di menu.

public:
 property int Depth { int get(); };
[System.ComponentModel.Browsable(false)]
public int Depth { get; }
[<System.ComponentModel.Browsable(false)>]
member this.Depth : int
Public ReadOnly Property Depth As Integer

Valore della proprietà

Livello in cui viene visualizzata una voce di menu.

Attributi

Esempio

Nell'esempio seguente viene illustrato come utilizzare la Depth proprietà per determinare la profondità di una voce di menu.


<%@ 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 Page_Load(Object sender, EventArgs e)
  {
    // If the Menu control contains any root nodes, perform a
    // preorder traversal of the tree and display the text of 
    // nodes with a depth of 2.
    if (NavigationMenu.Items.Count > 0)
    {

      // Iterate through the root menu items in the Items collection.
      foreach (MenuItem item in NavigationMenu.Items)
      {

        DisplayChildMenuText(item);

      }

    }
    else
    {

      Message.Text = "The Menu control does not have any items.";

    }
  }

  void DisplayChildMenuText(MenuItem item)
  {

    // Use the Depth property to determine the depth of a 
    // menu item. Display only items with a depth of 2.
    if (item.Depth == 2)
    {
      Message.Text += item.Text + "<br />";
    }

    // Iterate through the child menu items of the parent menu item 
    // passed into this method, and display their values.
    foreach (MenuItem childItem in item.ChildItems)
    {

      // Recursively call the DisplayChildMenuText method to
      // traverse the tree.
      DisplayChildMenuText(childItem);

    }

  }
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>MenuItem Depth Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>MenuItem Depth Example</h3>
    
      <asp:menu id="NavigationMenu"
        staticdisplaylevels="2"
        staticsubmenuindent="10" 
        orientation="Vertical"
        runat="server">
      
        <items>
          <asp:menuitem text="Home"
            tooltip="Home">
            <asp:menuitem text="Music"
              tooltip="Music">
              <asp:menuitem text="Classical"
                tooltip="Classical"/>
              <asp:menuitem text="Rock"
                tooltip="Rock"/>
              <asp:menuitem text="Jazz"
                tooltip="Jazz"/>
            </asp:menuitem>
            <asp:menuitem text="Movies"
              tooltip="Movies">
              <asp:menuitem text="Action"
                tooltip="Action"/>
              <asp:menuitem text="Drama"
                tooltip="Drama"/>
              <asp:menuitem text="Musical"
                tooltip="Musical"/>
            </asp:menuitem>
          </asp:menuitem>
        </items>
      
      </asp:menu>
      
      <hr/>
      
      Menu items with a depth of 2:<br/><br/>
      <asp:label id="Message" 
        runat="server"/>

    </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 Page_Load(ByVal sender As Object, ByVal e As EventArgs)
  
    ' If the Menu control contains any root menu items, perform a
    ' preorder traversal of the tree and display the text of 
    ' menu items with a depth of 2.
    If NavigationMenu.Items.Count > 0 Then

      ' Iterate through the root menu items in the Items collection.
      Dim item As MenuItem
      
      For Each item In NavigationMenu.Items

        DisplayChildMenuText(item)

      Next

    Else

      Message.Text = "The Menu control does not have any items."

    End If
      
  End Sub

  Sub DisplayChildMenuText(ByVal item As MenuItem)

    ' Use the Depth property to determine the depth of a 
    ' menu item. Display only items with a depth of 2.
    If item.Depth = 2 Then
      Message.Text += item.Text + "<br />"
    End If

    ' Iterate through the child menu items of the parent menu item 
    ' passed into this method, and display their values.
    Dim childItem As MenuItem
    
    For Each childItem In item.ChildItems

      ' Recursively call the DisplayChildMenuText method to
      ' traverse the tree.
      DisplayChildMenuText(childItem)

    Next

  End Sub
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>MenuItem Depth Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>MenuItem Depth Example</h3>
    
      <asp:menu id="NavigationMenu"
        staticdisplaylevels="2"
        staticsubmenuindent="10" 
        orientation="Vertical"
        runat="server">
      
        <items>
          <asp:menuitem text="Home"
            tooltip="Home">
            <asp:menuitem text="Music"
              tooltip="Music">
              <asp:menuitem text="Classical"
                tooltip="Classical"/>
              <asp:menuitem text="Rock"
                tooltip="Rock"/>
              <asp:menuitem text="Jazz"
                tooltip="Jazz"/>
            </asp:menuitem>
            <asp:menuitem text="Movies"
              tooltip="Movies">
              <asp:menuitem text="Action"
                tooltip="Action"/>
              <asp:menuitem text="Drama"
                tooltip="Drama"/>
              <asp:menuitem text="Musical"
                tooltip="Musical"/>
            </asp:menuitem>
          </asp:menuitem>
        </items>
      
      </asp:menu>
      
      <hr/>
      
      Menu items with a depth of 2:<br/><br/>
      <asp:label id="Message" 
        runat="server"/>

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

Commenti

Utilizzare la Depth proprietà per determinare la profondità della voce di menu. La profondità indica il livello in cui viene visualizzata una voce di menu e rappresenta il numero di livelli di gerarchia tra la voce di menu corrente e la voce di menu radice. Ad esempio, una voce di menu radice ha una profondità pari a 0. Una voce di sottomenu della voce di menu radice ha una profondità pari a 1 e così via.

Si applica a

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