Επεξεργασία

Κοινή χρήση μέσω

DataBoundControl.GetData Method

  • Reference

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Retrieves a DataSourceView object that the data-bound control uses to perform data operations.

protected:
 virtual System::Web::UI::DataSourceView ^ GetData();
protected virtual System.Web.UI.DataSourceView GetData ();
abstract member GetData : unit -> System.Web.UI.DataSourceView
override this.GetData : unit -> System.Web.UI.DataSourceView
Protected Overridable Function GetData () As DataSourceView

Returns

DataSourceView

The DataSourceView that the data-bound control uses to perform data operations. If the DataMember property is set, a specific, named DataSourceView is returned; otherwise, the default DataSourceView is returned.

Exceptions

InvalidOperationException

Both the DataSource and DataSourceID properties are set.

-or-

The DataMember property is set but a DataSourceView object by that name does not exist.

Examples

The following code example demonstrates how the GetData method is called to retrieve the DataSourceView object from the associated data source control and the Select method is called to retrieve the data. 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

The GetData method retrieves a DataSourceView object from the associated data source control by calling the GetDataSource method. If the DataSource property is used to identify a data source, a default DataSourceView object is created.

Applies to

See also