private void ButtonHandle()
{
ButtonList.AddRange(new List <UIButton> {
btnNumberOne,
btnNumberTwo,
btnNumberThree,
btnNumberFour,
btnNumberFive,
btnNumberSix,
btnNumberSeven,
btnNumberEight,
btnNumberNine,
btnNumberZero
});
foreach (var button in ButtonList)
{
button.TouchUpInside += setNumberToList;
}
}