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Control.OnDataBinding Method

Raises the DataBinding event.

Namespace: System.Web.UI
Assembly: System.Web (in system.web.dll)

'Declaration
Protected Overridable Sub OnDataBinding ( _
	e As EventArgs _
)
'Usage
Dim e As EventArgs

Me.OnDataBinding(e)
protected void OnDataBinding (
	EventArgs e
)
protected function OnDataBinding (
	e : EventArgs
)
Not applicable.

Parameters

e

An EventArgs object that contains the event data.

This method notifies a server control to perform any logic for binding data that is associated with it.

If you want to handle the DataBinding event, you should override this event-handling method. This ensures that all delegates attached to the DataBinding event are invoked.

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 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

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

    if (get_DataSource() != null) {
        // Clear any existing child controls.
        get_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 = get_DataSource().GetEnumerator();
        int i = 0;
        while (dataEnum.MoveNext()) {
            // Create an item.
            RepeaterItem item = new RepeaterItem(i, dataEnum.get_Current());
            // Initialize the item from the template.
            get_ItemTemplate().InstantiateIn(item);
            // Add the item to the ControlCollection.
            get_Controls().Add(item);
            i++;
        }
        // Prevent child controls from being created again.
        set_ChildControlsCreated(true);
        // Store the number of items created in view state for postback
        // scenarios.
        get_ViewState().set_Item("NumItems", (Int32)i);
    }
} //OnDataBinding

Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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