Control.IsTrackingViewState Control.IsTrackingViewState Control.IsTrackingViewState Control.IsTrackingViewState Property

定义

获取一个值,用于指示服务器控件是否会将更改保存到其视图状态中。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

属性值

如果控件标记为保存其状态,则为 true;否则为 falsetrue if the control is marked to save its state; otherwise, false.

示例

下面的示例重写DataBind自定义 ASP.NET 服务器控件中的方法。The following example overrides the DataBind method in a custom ASP.NET server control. 首先调用基OnDataBinding方法,然后ControlCollection使用对象。It begins by calling the base OnDataBinding method and then uses the ControlCollection object. ControlCollection.Clear方法删除所有子控件,并将ClearChildViewState方法删除这些子控件的任何已保存的视图状态设置。ControlCollection.Clear method to delete all the child controls and the ClearChildViewState method to delete any saved view-state settings for those child controls. 最后, ChildControlsCreated将属性设置为trueFinally, the ChildControlsCreated property is set to true. 然后,控件使用IsTrackingViewState属性来确定是否为控件启用了视图状态更改跟踪。The control then uses the IsTrackingViewState property to determine whether view-state change tracking is enabled for the control. 如果未启用, TrackViewState则调用方法。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

注解

有关使用此属性的示例自定义服务器控件,请参阅模板服务器控件示例For a sample custom server control that uses this property, see Templated Server Control Example

适用于

另请参阅