How to find out next character alphabetically?

Try this:

char letter = 'c';

if (letter == 'z')
    nextChar = 'a';
else if (letter == 'Z')
    nextChar = 'A';

else
    nextChar = (char)(((int)letter) + 1);

This way you have no trouble when the char is the last of the alphabet.

How about:

char first = 'c';
char nextChar = (char)((int) first + 1);

Perhaps the simplest way is a little function and an array of the 26 chars. Then you can decide what you want to return for 'z'.

Convert the character to a number, increment the number and then convert back.

But consider what will happen for "z" or "á" (Latin Small Leter A with Acute).

need to just add 1 in character you get next character. It works on ASCII values.

Try this :

public string GetNextAlphabetLetter(int indice) {
  return ((char)('A' + indice)).ToString();
}