学步园

   byte[] tmpaa = new byte[1]; //先定义一个全局变量，保存第一次接受的字头，因为第一次接受就是一个字节，这个字节是下次接受的字头
     bool isTou = false;//判断是不是第一次接受的字节，是的话，赋值给第二次接受的字节

     public string Readconn(SocketAsyncEventArgs e)
     {
         byte[] tmpa = new byte[e.BytesTransferred];
         if (tmpa.Length == 1)
         {
             isTou = true;
             tmpaa[0] = e.Buffer[0];

             return "cuowu";

         }
         else
         {

             string resRead = "";
             for (int i = 1; i < e.BytesTransferred; i++)
             {
                 if (isTou)
                 {
                     tmpa[0] = tmpaa[0];
                     tmpa[1] = tmpaa[0];
                     isTou = false;
                 }

                 tmpa[i] = e.Buffer[i - 1];
             }

             System.IO.Stream connection = new System.IO.MemoryStream(tmpa);

             List<string> output = new List<string>();
             string o = "";
             byte[] tmp = new byte[4];
             long count;
             while (true)
             {
                 tmp[3] = (byte)connection.ReadByte();
                 //if(tmp[3] == 220) tmp[3] = (byte)connection.ReadByte(); it sometimes happend to me that

                 //mikrotik send 220 as some kind of "bonus" between words, this fixed things, not sure about it though
                 if (tmp[3] == 255)
                 {
                     output.Add(o);
                     if (o.Substring(0, 5) == "!done" || o.Substring(0, 3) == "!re")
                     {
                         break;
                     }
                     else
                     {
                         o = "";
                         continue;
                     }
                 }
                 else
                 {
                     if (tmp[3] < 0x80)
                     {
                         count = tmp[3];
                     }
                     else
                     {
                         if (tmp[3] < 0xC0)
                         {
                             int tmpi = BitConverter.ToInt32(new byte[] { (byte)connection.ReadByte(), tmp[3], 0, 0 }, 0);
                             count = tmpi ^ 0x8000;
                         }
                         else
                         {
                             if (tmp[3] < 0xE0)
                             {
                                 tmp[2] = (byte)connection.ReadByte();
                                 int tmpi = BitConverter.ToInt32(new byte[] { (byte)connection.ReadByte(), tmp[2], tmp[3], 0 }, 0);
                                 count = tmpi ^ 0xC00000;
                             }
                             else
                             {
                                 if (tmp[3] < 0xF0)
                                 {
                                     tmp[2] = (byte)connection.ReadByte();
                                     tmp[1] = (byte)connection.ReadByte();
                                     int tmpi = BitConverter.ToInt32(new byte[] { (byte)connection.ReadByte(), tmp[1], tmp[2], tmp[3] }, 0);
                                     count = tmpi ^ 0xE0000000;
                                 }
                                 else
                                 {
                                     if (tmp[3] == 0xF0)
                                     {
                                         tmp[3] = (byte)connection.ReadByte();
                                         tmp[2] = (byte)connection.ReadByte();
                                         tmp[1] = (byte)connection.ReadByte();
                                         tmp[0] = (byte)connection.ReadByte();
                                         count = BitConverter.ToInt32(tmp, 0);
                                     }
                                     else
                                     {
                                         //Error in packet reception, unknown length
                                         break;
                                     }
                                 }
                             }
                         }
                     }
                 }

                 for (int i = 0; i < count; i++)
                 {
                     o += (Char)connection.ReadByte();
                 }
             }
             foreach (string item in output)
             {
                 resRead += item;
             }
             //output.Clear();
             return resRead;

         }
     }