Working with Strings C#

Question

Hi, i tryed to work with strings for challenges, but i came to a problem.
Whenever i tried to use any part of an numeral string as an int (via Convert.ToInt32(string[part]) ) it ended up with 49, 50 and so on, but never with the number it was on the string. You can see it in my Code "Magic Square" (https://code.sololearn.com/cADgEdj4zBm8/#cs) for the Challenge with the same name.
Can someone help me fixing it, or better explain my mistake?

Answer 1

instead of Convert.ToInt32(string[part])
use int.Parse(string[part].ToString())

because the Convert method with a character returns an ascii code

Answer 2

thanks a lot