曾有需求做个用户名中非法字符的判断，要求是只能输入中英文和数字，其他字符一律非法，故写了下边一个程序mark一下吧~~
NSString *testString = @"春1mianBU觉晓";
NSString *perchar;
int alength = [testString length];
for (int i = 0; i<alength; i++) {
char commitChar = [testString characterAtIndex:i];
NSString *temp = [testString substringWithRange:NSMakeRange(i,1)];
const char *u8Temp = [temp UTF8String];
if (3==strlen(u8Temp)){
NSLog(@"字符串中含有中文");
}else if((commitChar>64)&&(commitChar<91)){
NSLog(@"字符串中含有大写英文字母");
}else if((commitChar>96)&&(commitChar<123)){
NSLog(@"字符串中含有小写英文字母");
}else if((commitChar>47)&&(commitChar<58)){
NSLog(@"字符串中含有数字");
}else{
NSLog(@"字符串中含有非法字符");
}
}