CalculationBehavior
RadCalculator handles the whole calculation logic by its StandardCalculatorCalculationBehavior. It can be accessed by the CalculationBehavior property of the control.
It offers a convenient public API that can be used for any customization purposes.
Custom StandardCalculatorCalculationBehavior
1. Create a derivative of the StandardCalculatorCalculationBehavior class and override the OnButtonMouseUp and OnButtonKeyDown methods where it is possible to control what button action to be executed.
2. Restrict all memory commands considering the passed CalculatorButtonType. In addition to this, Keys.NumPad5 is also forbidden by the keyboard:
3. Apply the custom behavior to the CalculatorElement.CalculationBehavior property.