Show digits of Number, even when it is 0 (input:12 output:12.00)

Hey is there is simple way to show 12 as 12.00, when I convert it to string?
I can’t just add zeros, cause it also has inputs with digits, where only one 0 need to be added.

Some inputs and there espected outputs:

12    ->    12.00 
1.3   ->    1.30
0.2   ->    0.2
3.454 ->    3.45

I have tried this:

String.Format("{0:0.00}", Regex.Replace(VerkaufspreisInput.Text, 12);

Output 12

It’s the wrong function.

Thanks for help!

>Solution :

You can use ToString with N2, e.g.:

Console.WriteLine((12.00).ToString("N2"));

Will print 12.00.