进制格式转换 c#

Console.WriteLine("十六进制17的表示：" + Convert.ToInt32("17", 16));//即17是十六进制位  得到的结果是23 得到十进制数

public static string mdFiveGet(string mdNum)
{
String BinOne = string.Empty;
String BinAll = string.Empty;
char[] nums = mdNum.ToCharArray();
for (int i = 0; i < nums.Length; i++)
{
string number = nums[i].ToString();
int num = Int32.Parse(number, System.Globalization.NumberStyles.HexNumber);
BinOne = Convert.ToString(num, 2);
BinAll = BinAll + BinOne;
}
Console.WriteLine("BIN:" + BinAll);
return BinAll;

　　　　 private static string _test = "1";
static void Main(string[] args)
{
string a = "";

byte[] bytes4 = Encoding.GetEncoding("GB2312").GetBytes(_test);
string s4 = Encoding.GetEncoding("GB2312").GetString(bytes4);
foreach (byte bt in bytes4)
a += bt;
Console.WriteLine("字节流为：" + a);
Console.WriteLine("将字节流还原为字符串：" + s4);
Console.ReadKey();
}