Control.OnDataBinding(EventArgs) Control.OnDataBinding(EventArgs) Control.OnDataBinding(EventArgs) Control.OnDataBinding(EventArgs) Method

Definizione

Genera l'evento DataBinding.Raises the DataBinding event.

protected:
 virtual void OnDataBinding(EventArgs ^ e);
protected virtual void OnDataBinding (EventArgs e);
abstract member OnDataBinding : EventArgs -> unit
override this.OnDataBinding : EventArgs -> unit
Protected Overridable Sub OnDataBinding (e As EventArgs)

Parametri

e
EventArgs EventArgs EventArgs EventArgs

Oggetto EventArgs che contiene i dati dell'evento.An EventArgs object that contains the event data.

Esempi

Nell'esempio seguente viene illustrato come eseguire l'override di OnDataBinding metodo per aggiungere i controlli figlio del controllo padre da un'origine dati.The following example demonstrates how to override the OnDataBinding method to add child controls to the parent control from a data source.

// Override to create the repeated items from the DataSource.
protected override void OnDataBinding(EventArgs e) {
    base.OnDataBinding(e);

    if (DataSource != null) {
        // Clear any existing child controls.
        Controls.Clear();
        // Clear any previous view state for the existing child controls.
        ClearChildViewState();

        // Iterate over the DataSource, creating a new item for each data item.
        IEnumerator dataEnum = DataSource.GetEnumerator();
        int i = 0;
        while(dataEnum.MoveNext()) {

            // Create an item.
            RepeaterItem item = new RepeaterItem(i, dataEnum.Current);
            // Initialize the item from the template.
            ItemTemplate.InstantiateIn(item);
            // Add the item to the ControlCollection.
            Controls.Add(item);

            i++;
        }

        // Prevent child controls from being created again.
        ChildControlsCreated = true;
        // Store the number of items created in view state for postback scenarios.
        ViewState["NumItems"] = i;
    }
}
' Override to create the repeated items from the DataSource.
Protected Overrides Sub OnDataBinding(E As EventArgs)
    MyBase.OnDataBinding(e)

    If Not DataSource Is Nothing
        ' Clear any existing child controls.
        Controls.Clear()
        ' Clear any previous view state for the existing child controls.
        ClearChildViewState()

        ' Iterate over the DataSource, creating a new item for each data item.
        Dim DataEnum As IEnumerator = DataSource.GetEnumerator()
        Dim I As Integer = 0
        Do While (DataEnum.MoveNext())

            ' Create an item.
            Dim Item As RepeaterItemVB = New RepeaterItemVB(I, DataEnum.Current)
            ' Initialize the item from the template.
            ItemTemplate.InstantiateIn(Item)
            ' Add the item to the ControlCollection.
            Controls.Add(Item)

            I = I + 1
        Loop

        ' Prevent child controls from being created again.
        ChildControlsCreated = true
        ' Store the number of items created in view state for postback scenarios.
        ViewState("NumItems") = I
    End If
End Sub

Commenti

Questo metodo notifica a eseguire qualsiasi logica per associare i dati che sono associati un controllo server.This method notifies a server control to perform any logic for binding data that is associated with it.

Se si desidera gestire il DataBinding evento, è necessario eseguire l'override di questo metodo di gestione degli eventi.If you want to handle the DataBinding event, you should override this event-handling method. In questo modo si garantisce che tutti i delegati è collegato al DataBinding eventi vengono richiamati.This ensures that all delegates attached to the DataBinding event are invoked.

Si applica a

Vedi anche