BaseDataBoundControl.OnDataBound(EventArgs) Method

Reference

Definition

Namespace:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Important

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Raises the DataBound event.

protected:
 virtual void OnDataBound(EventArgs ^ e);

protected virtual void OnDataBound (EventArgs e);

abstract member OnDataBound : EventArgs -> unit
override this.OnDataBound : EventArgs -> unit

Protected Overridable Sub OnDataBound (e As EventArgs)

Parameters

e: EventArgs

An EventArgs object that contains the event data.

Examples

The following code example demonstrates how the OnDataBound method is used to raise the DataBound event by a derived data-bound control class. After using the GetData and PerformDataBinding methods to bind data to the control, the data-bound control raises the DataBound event to signal that data binding is complete. This code example is part of a larger example provided for the DataBoundControl class.

protected override void PerformSelect() {            

   // Call OnDataBinding here if bound to a data source using the
   // DataSource property (instead of a DataSourceID), because the
   // databinding statement is evaluated before the call to GetData.       
    if (!IsBoundUsingDataSourceID) {
        OnDataBinding(EventArgs.Empty);
    }            
    
    // The GetData method retrieves the DataSourceView object from  
    // the IDataSource associated with the data-bound control.            
    GetData().Select(CreateDataSourceSelectArguments(), 
        OnDataSourceViewSelectCallback);
    
    // The PerformDataBinding method has completed.
    RequiresDataBinding = false;
    MarkAsDataBound();
    
    // Raise the DataBound event.
    OnDataBound(EventArgs.Empty);
}

Protected Overrides Sub PerformSelect()

    ' Call OnDataBinding here if bound to a data source using the 
    ' DataSource property (instead of a DataSourceID) because the 
    ' data-binding statement is evaluated before the call to GetData.
    If Not IsBoundUsingDataSourceID Then
        OnDataBinding(EventArgs.Empty)
    End If

    ' The GetData method retrieves the DataSourceView object from the 
    ' IDataSource associated with the data-bound control.            
    GetData().Select(CreateDataSourceSelectArguments(), _
        AddressOf OnDataSourceViewSelectCallback)

    ' The PerformDataBinding method has completed.
    RequiresDataBinding = False
    MarkAsDataBound()

    ' Raise the DataBound event.
        OnDataBound(EventArgs.Empty)

End Sub

Remarks

This method notifies a server control that any data binding logic associated with the control has completed.

Important

The DataBind method is sealed on all controls derived from BaseDataBoundControl. Data-bound controls should override PerformDataBinding instead of the DataBind method to bind data. If DataBind is overridden, the OnDataBinding and OnDataBound events are raised out of order.

Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.

The OnDataBound method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors

When overriding OnDataBound(EventArgs) in a derived class, be sure to call the base class' OnDataBound(EventArgs) method so that registered delegates receive the event.

Applies to

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