I tried use the string.Replace() function, but it doesn\'t work right.
string test = \"AAA AA AA faseffs AEfAfse AFAEf AEFAEf\"; test.Replace(\'A\', \'C\'); labe
Strings are immutable in NET. Replace works building a new string with the replaced chars and returning it. You could assign the returned string to the same string used to call the Replace method (or to a new string variable)
test = test.Replace('A', 'C');