public void Reset()
{
Btn1 = null;
RaisePropertyChange(nameof(Btn1));
Btn2 = null;
RaisePropertyChange(nameof(Btn2));
Btn3 = null;
RaisePropertyChange(nameof(Btn3));
Btn4 = null;
RaisePropertyChange(nameof(Btn4));
Btn5 = null;
RaisePropertyChange(nameof(Btn5));
Btn6 = null;
RaisePropertyChange(nameof(Btn6));
Btn7 = null;
RaisePropertyChange(nameof(Btn7));
Btn8 = null;
RaisePropertyChange(nameof(Btn8));
Btn9 = null;
RaisePropertyChange(nameof(Btn9));
model.Reset();
}