MenuItemCollection.Contains(MenuItem) Methode

  • Referenz

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Bestimmt, ob das angegebene MenuItem-Objekt in der Auflistung vorhanden ist.

public:
 bool Contains(System::Web::UI::WebControls::MenuItem ^ c);
public bool Contains (System.Web.UI.WebControls.MenuItem c);
member this.Contains : System.Web.UI.WebControls.MenuItem -> bool
Public Function Contains (c As MenuItem) As Boolean

Parameter

c
MenuItem

Das zu suchende MenuItem.

Gibt zurück

Boolean

true, wenn das angegebene MenuItem-Objekt in der Auflistung enthalten ist, andernfalls false.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie mithilfe der Contains -Methode ermittelt wird, ob ein MenuItem Objekt in einem MenuItemCollection Objekt enthalten ist.


<%@ 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)
  {
    // Use the Contains method to determine whether the menu
    // item selected by the user is contained in the Items
    // collection of the Menu control. 
    if(NavigationMenu.Items.Contains(e.Item))
    {
      Message.Text = "You selected the root menu item.";
    }
    else
    {
      Message.Text = "You selected a submenu item.";
    }
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>MenuItemCollection Contains Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>MenuItemCollection Contains 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)
  
    ' Use the Contains method to determine whether the menu
    ' item selected by the user is contained in the Items
    ' collection of the Menu control. 
    If NavigationMenu.Items.Contains(e.Item) Then
    
      Message.Text = "You selected the root menu item."
    
    Else
    
      Message.Text = "You selected a submenu item."
    
    End If
      
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>MenuItemCollection Contains Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>MenuItemCollection Contains 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>

Hinweise

Verwenden Sie die Contains -Methode, um zu bestimmen, ob ein MenuItem Objekt im aktuellen MenuItemCollection Objekt enthalten ist. Die MenuItem Eigenschaften und werden mit dem übergebenen Wert verglichen. Diese Methode wird häufig verwendet, um zu testen, ob ein MenuItem Objekt vorhanden ist, bevor eine Aufgabe ausgeführt wird, z. B. das Hinzufügen oder Entfernen eines Menüelements aus der Auflistung.

Gilt für:

Weitere Informationen