十进制转二进制

/**
 转化为十进制

 @param binary 二进制的数据
 @return 数据结果
 */
- (NSString *)convertDecimalSystemFromBinarySystem:(NSString *)binary
{
    NSInteger ll = 0 ;
    NSInteger  temp = 0 ;
    for (NSInteger i = 0; i < binary.length; i ++){
        
        temp = [[binary substringWithRange:NSMakeRange(i, 1)] intValue];
        temp = temp * powf(2, binary.length - i - 1);
        ll += temp;
    }
    
    NSString * result = [NSString stringWithFormat:@"%ld",ll];
    
    return result;
}

十进制转二进制

/**
 转化为二进制

 @param decimal 十进制的数据
 @return 二进制的结果
 */
- (NSString *)getBinaryByDecimal:(NSInteger)num {
    NSInteger remainder = 0;      //余数
    NSInteger divisor = 0;        //除数
    
    NSString * prepare = @"";
    
    while (true){
        
        remainder = num%2;
        divisor = num/2;
        num = divisor;
        prepare = [prepare stringByAppendingFormat:@"%ld",remainder];
        
        if (divisor == 0){
            
            break;
        }
    }
    
    NSString * result = @"";
    
    for (NSInteger i = prepare.length - 1; i >= 0; i --){
        
        result = [result stringByAppendingFormat:@"%@",
                  [prepare substringWithRange:NSMakeRange(i , 1)]];
    }
    
    return result;
}

十进制转十六进制

/**
 十进制转十六进制

 @param tmpid 数据
 @return 结果
 */
-(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:@"%lli",ttmpig];
                
        }
        str = [nLetterValue stringByAppendingString:str];
        if (tmpid == 0) {
            break;
        }
        
    }
    return str;
}