how to get many Values from same InputBox and assign them to Variabls in c#? : i have 4 Buttons: button_1 writes in the InputBox the number 1, button_plus writes in the same Inputbox "+", the button_2 writes the number 2. finally stands in the Inputbox: 1 + 2


now i want to use the button_Equals, to get 1 + 2 from the Inputbox and assing them to a variable. I used int.Parse(), Int32.Parse() and Convert.ToInt32() to get both numbers the 1 und the 2, but it doesn't work:

      r = int.Parse(textBox1.Text);
      s =int.Parse(textBox1.Text);

id like to assign 1 to r and 2 to s but the Programm kolaps, when i click on the Button_Equals and it Shows the following message: 

> System.FormatException

would you please help me how to get the both numbers in each in a variable? ill be so thankfull

