TdxCustomGaugeControl.BeginUpdate Method

Prevents a Gauge Control instance from being updated until either the EndUpdate or CancelUpdate method is invoked.

Declaration

procedure BeginUpdate;

Remarks

This procedure disables control repainting. If the BeginUpdate method is invoked, any changes within the ExpressGauge control are not visualized until the EndUpdate method is called. The BeginUpdate/EndUpdate pair of methods must enclose the code updating the gauge control. Every call of the BeginUpdate method increments the internal counter by one. Every call of the EndUpdate method decrements this counter by one. The gauge control can refresh itself only when the internal counter is 0.

The EndUpdate method also triggers gauge control invalidation. If no changes are made, you can call the CancelUpdate method instead to allow further updates of the control. Unlike EndUpdate, the CancelUpdate method does not invalidate the gauge control. If you call the CancelUpdate method after performing changes affecting the ExpressGauge control’s appearance, an exception will occur.