根据ASCII码值对输入的内容做不同的处理
int ascii = [base64 characterAtIndex:0];
int ascii_a = [@"a" characterAtIndex:0];//转ASCII码
int ascii_z = [@"z" characterAtIndex:0];
int ascii_A = [@"A" characterAtIndex:0];
int ascii_Z = [@"Z" characterAtIndex:0];
int ascii_0 = [@"0" characterAtIndex:0];
int ascii_9 = [@"9" characterAtIndex:0];
if( ascii >= ascii_A && ascii <= ascii_Z){
NSLog(@"A-Z: %d",ascii);
resultStr = base64;
}else if( ascii >= ascii_a && ascii <= ascii_z){
NSLog(@"a-z :%d",ascii);
resultStr = base64;
}else if( ascii >= ascii_0 && ascii <= ascii_9){
NSLog(@"0-9 :%d",ascii);
}
