Building a Calculator using C#

Question

I would like to build a basic calculator using C#.

However, I aim to build one which performs calculation only after the equal button is clicked.

For example, when someone type in "10+12/2-2", the calculator will display "10+12/2-2 = 10" after the "=" button is clicked.

Any idea how to do it?

Thank you very much for your help.