ControlCollection.Item[Int32] Proprietà

  • Riferimento

Definizione

Spazio dei nomi:
System.Web.UI
Assembly:
System.Web.dll

Ottiene un riferimento al controllo server nella posizione di indice specificata nell'oggetto ControlCollection.

public:
 virtual property System::Web::UI::Control ^ default[int] { System::Web::UI::Control ^ get(int index); };
public virtual System.Web.UI.Control this[int index] { get; }
member this.Item(int) : System.Web.UI.Control
Default Public Overridable ReadOnly Property Item(index As Integer) As Control

Parametri

index
Int32

Posizione dei controlli server nel controllo ControlCollection.

Valore della proprietà

Control

Il riferimento al controllo.

Eccezioni

ArgumentOutOfRangeException

Il valore del parametro index è minore di zero oppure uguale a o maggiore di Count.

Esempio

Nell'esempio di codice seguente viene utilizzata la proprietà per specificare la posizione dell'indice Item[] di un controllo figlio rimosso in una Remove chiamata al metodo. Questa operazione viene eseguita dalla myButton.Controls.Remove sintassi.


<!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)
   {
       Response.Write("<h2>Sample for ControlCollection Class</h2>");

       LiteralControl myLiteralControl 
           = new LiteralControl("ChildControl1");

       myButton.Controls.Add(myLiteralControl);
       myButton.Controls.AddAt(1,new LiteralControl("ChildControl2"));

       System.Array myControlCollectionArray 
           = Array.CreateInstance(typeof(object), 
               myButton.Controls.Count);
       myButton.Controls.CopyTo(myControlCollectionArray,0);

       IEnumerator myEnumerator1 = 
           myControlCollectionArray.GetEnumerator();

       while (myEnumerator1.MoveNext())
       {
           object myObject = myEnumerator1.Current;

           if(myObject.GetType().Equals(typeof(LiteralControl)))
           {
               LiteralControl childControl = 
                   (LiteralControl)myEnumerator1.Current;
               Response.Write("<p style=\"font-weight:bold\">");
               Response.Write("This is the  text of the child Control:" 
                   + Server.HtmlEncode(childControl.Text));
           }
       }

       myButton.Controls.Remove(myButton.Controls[0]);
       Response.Write("</p><p style=\"font-weight:bold\">");
       Response.Write("ChildControl1 is removed<br />");
       Response.Write("The count of ControlCollection = "
           + myButton.Controls.Count.ToString() + "</p>");
       myButton.Controls.Clear();
   }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

        <asp:Button ID="myButton" Text="Sample ServerControl" 
            Runat="server"></asp:Button>

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


<!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)

        Response.Write("<h2>Sample for ControlCollection Class</h2>")
        Dim myLiteralControl As LiteralControl _
            = New LiteralControl("ChildControl1")

        myButton.Controls.Add(myLiteralControl)
        myButton.Controls.AddAt(1, New LiteralControl("ChildControl2"))

        Dim myControlCollectionArray As System.Array = _
            Array.CreateInstance(GetType(Object), _
                myButton.Controls.Count)
        myButton.Controls.CopyTo(myControlCollectionArray, 0)

        Dim myEnumerator1 As IEnumerator = _
            myControlCollectionArray.GetEnumerator()

        While myEnumerator1.MoveNext()
            Dim myObject As Object = myEnumerator1.Current

            If myObject.GetType().Equals(GetType(LiteralControl)) Then
                Dim childControl As LiteralControl _
                    = CType(myEnumerator1.Current, LiteralControl)
                Response.Write("<p style=""font-weight:bold"">")
                Response.Write("This is the  text of the child Control:" _
                    & Server.HtmlEncode(childControl.Text))
            End If
        End While

        myButton.Controls.Remove(myButton.Controls(0))
        Response.Write("</p><p style=""font-weight:bold"">ChildControl1 is removed")
        Response.Write("<br />The count of ControlCollection = " _
            & myButton.Controls.Count.ToString() & "</p>")
        myButton.Controls.Clear()

    End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Sample for ControlCollection Class</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

        <asp:Button ID="myButton" Text="Sample ServerControl" 
            Runat="server"></asp:Button>
    
    </div>
    </form>
</body>
</html>

Si applica a

Vedi anche