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MenuItemCollection.IndexOf(MenuItem) Metodo

Definizione

Determina l'indice dell'oggetto MenuItem specificato nell'insieme.

public:
 int IndexOf(System::Web::UI::WebControls::MenuItem ^ value);
public int IndexOf (System.Web.UI.WebControls.MenuItem value);
member this.IndexOf : System.Web.UI.WebControls.MenuItem -> int
Public Function IndexOf (value As MenuItem) As Integer

Parametri

value
MenuItem

La classe MenuItem da individuare.

Restituisce

Int32

Indice in base zero della prima occorrenza di value all'interno della classe MenuItemCollection corrente, se presente; in caso contrario, -1.

Esempio

Nell'esempio di codice seguente viene illustrato come utilizzare il IndexOf metodo per determinare l'indice di un MenuItem oggetto all'interno di un MenuItemCollection oggetto .


<%@ 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 NavigationMenu_MenuItemClick(Object sender, MenuEventArgs e)
  {

    // Retrieve the parent menu item of the selected menu item.
    MenuItem parent = e.Item.Parent;

    // Determine whether the selected menu item is a 
    // root menu item. Root menu items are stored in
    // a Menu control's Items collection. Other menu
    // items are stored in the parent menu item's
    // ChildItems collection.
    if (parent != null)
    {
      Message.Text = "The " + e.Item.Text + 
        " menu item has an index of " +
        parent.ChildItems.IndexOf(e.Item).ToString() +
        " in the parent menu item's ChildItems collection.";
    }
    else
    {
      Message.Text = "The " + e.Item.Text +
        " menu item has an index of " +
        NavigationMenu.Items.IndexOf(e.Item).ToString() +
        " in the Menu control's Items collection.";
    }

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>MenuItemCollection IndexOf Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>MenuItemCollection IndexOf Example</h3>
    
      Select an item from the menu.
      <br/><br/>
    
      <asp:menu id="NavigationMenu"
        orientation="Vertical"
        target="_blank"
        onmenuitemclick="NavigationMenu_MenuItemClick"  
        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/>
      
      <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 NavigationMenu_MenuItemClick(ByVal sender As Object, ByVal e As MenuEventArgs)

    ' Retrieve the parent menu item of the selected menu item.
    Dim parent As MenuItem = e.Item.Parent

    ' Determine whether the selected menu item is a 
    ' root menu item. Root menu items are stored in
    ' a Menu control's Items collection. Other menu
    ' items are stored in the parent menu item's
    ' ChildItems collection.
    If parent IsNot Nothing Then
    
      Message.Text = "The " & e.Item.Text & _
        " menu item has an index of " & _
        parent.ChildItems.IndexOf(e.Item).ToString() & _
        " in the parent menu item's ChildItems collection."
    
    Else
    
      Message.Text = "The " & e.Item.Text & _
        " menu item has an index of " & _
        NavigationMenu.Items.IndexOf(e.Item).ToString() & _
        " in the Menu control's Items collection."
    
    End If

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>MenuItemCollection IndexOf Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>MenuItemCollection IndexOf Example</h3>
    
      Select an item from the menu.
      <br/><br/>
    
      <asp:menu id="NavigationMenu"
        orientation="Vertical"
        target="_blank"
        onmenuitemclick="NavigationMenu_MenuItemClick"  
        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/>
      
      <asp:label id="Message" 
        runat="server"/>
        
    </form>
  </body>
</html>

Commenti

Utilizzare il IndexOf metodo per determinare l'indice dell'oggetto specificato MenuItem nell'oggetto corrente MenuItemCollection . Se la voce di menu non è presente nell'insieme, il metodo restituisce -1.

Nota

Se la voce di menu specificata viene visualizzata più volte nell'insieme, viene restituito l'indice della prima occorrenza.

Si applica a

Vedi anche