Control.OnDataBinding(EventArgs) Methode

Definition

Löst das DataBinding-Ereignis aus.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)

Parameter

e
EventArgs

Ein EventArgs-Objekt, das die Ereignisdaten enthält.An EventArgs object that contains the event data.

Beispiele

Im folgenden Beispiel wird veranschaulicht, wie die OnDataBinding-Methode überschrieben wird, um dem übergeordneten Steuerelement aus einer Datenquelle untergeordnete Steuerelemente hinzuzufügen.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

Hinweise

Diese Methode benachrichtigt ein Server Steuerelement, eine beliebige Logik für das Binden von Daten auszuführen, die ihm zugeordnet sind.This method notifies a server control to perform any logic for binding data that is associated with it.

Wenn Sie das DataBinding-Ereignis behandeln möchten, sollten Sie diese Ereignis Behandlungsmethode überschreiben.If you want to handle the DataBinding event, you should override this event-handling method. Dadurch wird sichergestellt, dass alle an das DataBinding Ereignis angefügten Delegaten aufgerufen werden.This ensures that all delegates attached to the DataBinding event are invoked.

Gilt für:

Siehe auch