自己写的一个帧处理代码，请多多指教

 1 //USB读取缓存区
 2         static byte[] readBuffer;
 3         //帧缓存区
 4         static byte[] frameBuffer;
 5         //帧缓存区中等待处理标记
 6         static int _getIndex;
 7         static int GetIndex
 8         {
 9             get { return _getIndex; }
10             set
11             {
12                 if (value > 0)
13                     _getIndex = (value >= frameBuffer.Length) ? (value - frameBuffer.Length) : value;
14                 else
15                     _getIndex = 0;
16             }
17         }
18         //帧缓存区中已经接收到的标记
19         static int _nowIndex;
20         static int NowIndex
21         {
22             get { return _nowIndex; }
23             set
24             {
25                 if (value > 0)
26                     _nowIndex = (value >= frameBuffer.Length) ? (value - frameBuffer.Length) : value;
27                 else
28                     _nowIndex = 0;
29             }
30         }
31         static int indexTmp;       
32         //帧处理当前状态
33         static myEnums.FrameCheckState FrameState = myEnums.FrameCheckState.HandleStart;
34         //帧处理需要用的全局变量
35         static int getLength = 0, getCmd = 0;
36         static byte[] bgetLength = new byte[2], bgetCmd = new byte[2];

 1 /// <summary>
 2         /// 线程循环读取USB缓冲区
 3         /// </summary>
 4         static void ReadCmd()
 5         {
 6             byte[]buffer=new byte[usbReader.ReadBufferSize];
 7             int transferlength=0;
 8             try
 9             {
10                 while(true)
11                 {
12                     usbReader.Read(buffer, Consts.ReadTimeOut, out transferlength);
13 
14                     if(transferlength!=0)
15                     {
16                         for(int i=0;i<transferlength;i++)
17                         {
18                             frameBuffer[GetIndex] = buffer[i];
19                             GetIndex++;
20 
21                             //Console.Write(buffer[i].ToString("X2") + " ");
22                         }
23                         //Console.WriteLine();
24 
25                         GetFrameHandle();
26                     }
27                     Thread.Sleep(Consts.ReadSleepTime);
28                 }
29             }
30             catch
31             {
32                 Console.WriteLine("读取USB错误");
33             }
34         }

  1 /// <summary>
  2         /// 帧处理方法
  3         /// </summary>
  4         private static void GetFrameHandle()
  5         {
  6             while (true)
  7             {
  8                 if (NowIndex == GetIndex)
  9                     return;
 10 
 11                 switch (FrameState)
 12                 {
 13                     case myEnums.FrameCheckState.HandleStart:
 14                         if (frameBuffer[NowIndex] == ‘<‘)
 15                             FrameState = myEnums.FrameCheckState.OneMark;
 16 
 17                         NowIndex++;
 18                         break;
 19 
 20                     case myEnums.FrameCheckState.OneMark:
 21                         if (frameBuffer[NowIndex] == ‘<‘)
 22                         {
 23                             indexTmp = NowIndex;
 24                             FrameState = myEnums.FrameCheckState.TwoMark;
 25                         }
 26                         else
 27                             FrameState = myEnums.FrameCheckState.HandleStart;
 28 
 29                         NowIndex++;
 30                         break;
 31 
 32                     case myEnums.FrameCheckState.TwoMark:
 33                         FrameState = myEnums.FrameCheckState.CmdOne;
 34                         bgetCmd[0] = frameBuffer[NowIndex];
 35                         NowIndex++;
 36                         break;
 37 
 38                     case myEnums.FrameCheckState.CmdOne:
 39                         FrameState = myEnums.FrameCheckState.CmdTwo;
 40                         bgetCmd[1] = frameBuffer[NowIndex];
 41                         getCmd = BitConverter.ToInt16(bgetCmd, 0);
 42                         NowIndex++;
 43                         break;
 44 
 45                     case myEnums.FrameCheckState.CmdTwo:
 46                         FrameState = myEnums.FrameCheckState.LenghtOne;
 47                         bgetLength[0] = frameBuffer[NowIndex];
 48                         NowIndex++;
 49                         break;
 50 
 51                     case myEnums.FrameCheckState.LenghtOne:
 52                         FrameState = myEnums.FrameCheckState.LenghtTwo;
 53                         bgetLength[1] = frameBuffer[NowIndex];
 54                         getLength = BitConverter.ToInt16(bgetLength, 0);
 55                         NowIndex++;
 56                         break;
 57 
 58                     case myEnums.FrameCheckState.LenghtTwo:
 59                         //获取到的帧长度超过缓冲池的长度，或者比12小，说明接收到的数据是错误的
 60                         //12是因为能接收到的信息，最短的长度为12.
 61                         if (getLength > frameBuffer.Length || getLength < 12)
 62                         {
 63                             FrameState = myEnums.FrameCheckState.HandleStart;
 64                             return;
 65                         }
 66 
 67                         //6是因为 ‘<<‘+cmd+length=6，NowIndex此时指在length的下一位。
 68                         if (NowIndex > GetIndex)
 69                         {
 70                             if (getLength > (GetIndex + frameBuffer.Length - NowIndex + 6))
 71                                 return;
 72                         }
 73                         else
 74                         {
 75                             if (getLength > GetIndex - NowIndex + 6)
 76                                 return;
 77                         }
 78 
 79                         DataBeans.Frame myFrame = new DataBeans.Frame();
 80                         byte[] myData = new byte[getLength];
 81                         myFrame.cmd = getCmd;
 82                         myFrame.length = getLength;
 83                         myFrame.data = myData;
 84 
 85                         myFrame.data[0] = 0x3C;
 86                         myFrame.data[1] = 0x3C;
 87                         myFrame.data[2] = bgetCmd[0];
 88                         myFrame.data[3] = bgetCmd[1];
 89                         myFrame.data[4] = bgetLength[0];
 90                         myFrame.data[5] = bgetLength[1];
 91                         for (int i = 6; i < getLength; i++)
 92                         {
 93                             myFrame.data[i] = frameBuffer[NowIndex];
 94                             NowIndex++;
 95                         }
 96 
 97                         //Console.Write("\t\t");
 98                         //for (int i = 0; i < myFrame.data.Length;i++ )
 99                         //{
100                         //    Console.Write(myFrame.data[i].ToString("X2") + " ");
101                         //}
102                         //Console.WriteLine();
103 
104                         //帧的最后的确是结束标记‘>>‘，视为完整的一帧，送入队列
105                         if (myFrame.data[getLength - 1] == ‘>‘ && myFrame.data[getLength - 2] == ‘>‘)
106                             DataBeans.DataLists.setFrame(myFrame);
107                         //否则的话，不是一个正确的帧，回退到起始标记的下一位处重新做帧扫描
108                         else
109                             NowIndex = indexTmp;                     
110 
111                         FrameState = myEnums.FrameCheckState.HandleStart;
112                         break;
113 
114                     default:
115                         FrameState = myEnums.FrameCheckState.HandleStart;
116                         break;
117                 }
118             }
119         }