【iOS知识学习】_objective-c 十进制转换成16进制

-(NSString *)ToHex:(long long int)tmpid
{
    NSString *nLetterValue;
    NSString *str =@"";
    long long int ttmpig;
    for (int i = 0; i<9; i++) {
     ttmpig=tmpid%16;
    tmpid=tmpid/16;
    switch (ttmpig)
    {
        case 10:
            nLetterValue =@"A";break;
        case 11:
            nLetterValue =@"B";break;
        case 12:
            nLetterValue =@"C";break;
        case 13:
            nLetterValue =@"D";break;
        case 14:
            nLetterValue =@"E";break;
        case 15:
            nLetterValue =@"F";break;
        default:nLetterValue=[[NSString alloc]initWithFormat:@"%i",ttmpig];
            
    }
        str = [nLetterValue stringByAppendingString:str];
        if (tmpid == 0) {
            break;
        }

    }
    return str;
}