is it problem in visual studio or from me c#

Question

visual studio said to me (wrong in formatting )also I did try change the formatting but no interest

Answer 1

You convert string in textbox to a string, why?

Answer 2

what you mean and how i can do it

Answer 3

look this code
double p =Convert.Todouble(textbox1);
visual studio said me wrong in formatting After run the application
my application is calculatore

Answer 4

sorry double i mean

Answer 5

i did like this textbox1.text but it is not work

Answer 6

you mean change the letter capital