Control.OnDataBinding(EventArgs) Metoda

Definicja

Podnosi DataBinding zdarzenie.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)

Parametry

e
EventArgs

EventArgsObiekt, który zawiera dane zdarzenia.An EventArgs object that contains the event data.

Przykłady

W poniższym przykładzie pokazano, jak zastąpić OnDataBinding metodę, aby dodać kontrolki podrzędne do kontrolki nadrzędnej ze źródła danych.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

Uwagi

Ta metoda powiadamia formant serwera w celu wykonania dowolnej logiki dotyczącej powiązań skojarzonych z nią danych.This method notifies a server control to perform any logic for binding data that is associated with it.

Jeśli chcesz obsłużyć DataBinding zdarzenie, należy przesłonić tę metodę obsługi zdarzeń.If you want to handle the DataBinding event, you should override this event-handling method. Gwarantuje to, że wszystkie Delegaty dołączone do DataBinding zdarzenia są wywoływane.This ensures that all delegates attached to the DataBinding event are invoked.

Dotyczy

Zobacz też