Prevents the collection from being updated until the ChartCollectionBase.EndUpdate method is called.
The BeginUpdate and ChartCollectionBase.EndUpdate methods are intended to be used to implement batch modifications. This allows you to prevent excessive updates when performing multiple modifications with chart element collections at the same time. To do this, enclose the code that makes the changes within calls to these methods.
The BeginUpdate and EndUpdate methods use an internal counter to implement their functionality. The counter's initial value is 0. A call to the BeginUpdate method increments this counter by one. A call to the EndUpdate method decrements this counter by one and if its new value is zero, a change notification is generated. This means that each call to BeginUpdate must be paired with a call to EndUpdate. If a call to BeginUpdate is made but without a corresponding call to EndUpdate afterwards or EndUpdate is not called because an exception occurred, the View will no longer respond to changes. To ensure that EndUpdate is always called even if an exception occurs, wrap any calls to these methods in a try...finally statement.
If you want to apply all the changes made since the BeginUpdate method was last called, and no notification events are to be raised, then the ChartCollectionBase.CancelUpdate method should be used.