@ @ Ansi turn utf-8 Initializing 'char *' with an expression of type 'const void *' dis

My development environment is MAC 10.7.3 + Xcode 4.3 + sdk5.1
Because some program interface, the data files used by the program is ansi coded
In the group found a post is converted by the C library, but there is a warning written on:
In the code
char * ansiString = [ansiData bytes];
Tips on
Initializing 'char *' with an expression of type 'const void *' discards qualifiers

Consult heroes:
First, there is no better and more direct way to deal with ansi character set;
Second, the above warning there any good way to deal with it? Thank you!

Reply:
Ah okay
warning
Want to deal with the case to

const char * ansiString = (const char *) [ansiData bytes];
Reply:
Oh, thank reminder, under the help of heroes to solve, not added const modification, but on the right side added a char * can be