一，测试Demo

namespace 不同编码下的中英文字符大小{    class Program    {        static void Main(string[] args)        {            ShowCode();        }        private static void ShowCode() {            string[] strArray = { "b","abc","乙","甲乙丙丁"};            byte[] buffer;            string mode, back;            foreach (string  str in strArray)            {                for (int i=0; i<=2; i++)                {                    if (i==0) //ASCII编码                    {                        buffer = Encoding.ASCII.GetBytes(str);                        back = Encoding.ASCII.GetString(buffer, 0, buffer.Length);                        mode = "ASCII";                    }                    else if(i==1)  //UTF8编码                    {                        buffer = Encoding.UTF8.GetBytes(str);                        back = Encoding.UTF8.GetString(buffer, 0, buffer.Length);                        mode = "UTF8";                    }                    else           //Unicode编码                    {                        buffer = Encoding.Unicode.GetBytes(str);                        back = Encoding.Unicode.GetString(buffer, 0, buffer.Length);                        mode = "Unicode";                    }                    Console.WriteLine("编码方式:{0} ;字符串:{1} ;长度:{2}", mode, str, buffer.Length);                    Console.WriteLine("编码后的字节数组:");                    for (int j = 0; j <=buffer.Length-1; j++)                    {                        Console.WriteLine("  "+buffer[j]+"  ");                     }                    Console.WriteLine("\n编码后字符为:{0} \n",back);                                    }                Console.WriteLine("----------------------------------------------------------");            }                }    }}

  二，结果如下

          

   b只有在Unicode下面编码为2字节，读到的byte[1]被编码为了0；ASCII码和UTF-8编码相同。

Unicode编码每个字节后面都补了个0；

对于中文：

ASCII码编码后连外星人都读不出来了；

UTF8编码出了3个字节；

Unicode出来了两个字节；