Επεξεργασία

Κοινή χρήση μέσω

Control.IsTrackingViewState Property

  • Reference

Definition

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

Gets a value that indicates whether the server control is saving changes to its view state.

protected:
 property bool IsTrackingViewState { bool get(); };
protected bool IsTrackingViewState { get; }
member this.IsTrackingViewState : bool
Protected ReadOnly Property IsTrackingViewState As Boolean

Property Value

Boolean

true if the control is marked to save its state; otherwise, false.

Examples

The following example overrides the DataBind method in a custom ASP.NET server control. It begins by calling the base OnDataBinding method and then uses the ControlCollection object. ControlCollection.Clear method to delete all the child controls and the ClearChildViewState method to delete any saved view-state settings for those child controls. Finally, the ChildControlsCreated property is set to true. The control then uses the IsTrackingViewState property to determine whether view-state change tracking is enabled for the control. If it is not enabled, the TrackViewState method is called.

public override void DataBind() 
{
   base.OnDataBinding(EventArgs.Empty);
   // Reset the control's state.
   Controls.Clear();
   // Check for HasChildViewState to avoid unnecessary calls to ClearChildViewState.
   if (HasChildViewState)
      ClearChildViewState();
   ChildControlsCreated = true;
   if (!IsTrackingViewState)
      TrackViewState();
}

Public Overrides Sub DataBind()
   MyBase.OnDataBinding(EventArgs.Empty)
   ' Reset the control's state.
   Controls.Clear()
   ' Check for HasChildViewState to avoid unnecessary calls to ClearChildViewState.
   If HasChildViewState Then
      ClearChildViewState()
   End If
   ChildControlsCreated = True
   If Not IsTrackingViewState Then
      TrackViewState()
   End If
End Sub

Remarks

For a sample custom server control that uses this property, see Templated Server Control Example.

Applies to

See also