如何把c语言字符串转成oc字符串

NSString *str = [[NSString alloc] initWithUTF8String: "123456"];

[str release];

或者

//不用释放内存
NSString *str = [NSString stringWithFormat:@"i has %i and %.2f", 19, 1.223f];

initWithUTF8String -> stringWithUTF8String
initWithFormat -> stringWithFormat