/// <summary>
/// 读取指定配置文件，从x位置开始的n个字节数据
/// </summary>
/// <param name="destid"></param>
/// <param name="data"></param>
/// <returns></returns>
public static byte[] ReadDataFile(byte destid, ReadFile.Parameter para)
{
byte[] donedata;
byte[] data = GetData(para);
PrepareData.Msg_Bus _frame = new PrepareData.Msg_Bus();
_frame.flag = PrepareData.BUS_FRAME_FLAG;
_frame.srcID = MSGEncoding.srcID;
_frame.destID = destid;
_frame.msgDir = (byte)MSGEncoding.MsgDir.Request;
_frame.msgVer = MSGEncoding.msgVer;
_frame.msgType = (byte)MSGEncoding.MsgType.ReadFile;
_frame.msgSubType = (byte)MSGEncoding.ReadFile.ReadDataFile;
_frame.dataLen = (ushort)data.Length;
donedata = PrepareData.MergeMsg(ref _frame, data);
return(donedata);
}
/// <summary>
/// 正好占用八个字节的数据域，所以不采用list转array
/// </summary>
/// <param name="para"></param>
/// <returns></returns>
public static byte[] GetData(ReadFile.Parameter para)
{
byte[] tempdata = new byte[12];
byte[] temp = ByteStruct.StructToBytes(para.filename);
Array.Copy(temp, tempdata, 8);
//tempdata[0] = (byte)para.filename;
//tempdata[1] = (byte)(para.filename >> 8);
//tempdata[2] = (byte)(para.filename >> 16);
//tempdata[3] = (byte)(para.filename >> 24);
//tempdata[4] = (byte)(para.filename >> 32);
//tempdata[5] = (byte)(para.filename >> 24);
//tempdata[6] = (byte)(para.filename >> 24);
//tempdata[7] = (byte)(para.filename >> 24);
tempdata[8] = (byte)para.start;
tempdata[9] = (byte)(para.start >> 8);
tempdata[10] = (byte)para.readbytes;
tempdata[11] = (byte)(para.readbytes >> 8);
return(tempdata);
}
/// <summary>
/// 函数内完成交互，直到接收完成
/// 返回数据为空，且error为0x00，说明文件读取完成
/// 返回错误代码，且数据域为空为产生错误，例如：找不到文件
/// 返回数据域不为空，且error为0x00，说明正常读取文件
/// </summary>
/// <param name="b_recvframe">接收到的字节数组,未拆包的</param>
/// <param name="error">错误代码</param>
/// <returns>已接收多少字节</returns>
public static int MsgHandle(HandleData.TypeRet hdtr,
byte[] b_recvframe, ref ushort error)
{
//执行状态字和文件数据
byte[] recvdata;
//字节型执行状态字
byte[] _statecode = new byte[2];
//不包括执行状态字和CRC校验的文件数据
byte[] filedata;
//转换为ushort类型的执行状态字
ushort statecode;
//文件数据的长度（不包括执行状态字和CRC校验）
int datalen = 0;
int donerecvinmen = 0;
byte packetnum = hdtr.packetnum;
ReadFile.Parameter sender = (ReadFile.Parameter)Define.index_obj[packetnum];
switch (HandleData.TypeofFrame(b_recvframe).frametype)
{
//长帧
//statecode == 0表示无错误，且为长帧，表示肯定datalen肯定大于0
//如果datalen == 0则肯定为短帧情况，且表示文件接收完成
case 1:
{ //去除了CRC校验2字节（包括执行状态字和文件数据）
recvdata = new byte[b_recvframe.Length - PrepareData.BUS_FRAME_MINLEN - 2];
Array.Copy(b_recvframe, PrepareData.BUS_FRAME_MINLEN, recvdata, 0,
recvdata.Length);
Array.Copy(recvdata, 0, _statecode, 0, 2);
statecode = BitConverter.ToUInt16(_statecode, 0);
//去除了返回状态字2字节
datalen = recvdata.Length - 2;
//不能出现状态执行为0且数据长度为0的情况
//因为这是长帧，这种情况只能出现在短帧的情况下
//if (0 == statecode && datalen > 0)
if (0 == statecode)
{
//不包括执行状态字和CRC校验码的文件数据
filedata = new byte[datalen];
Array.Copy(recvdata, 2, filedata, 0, datalen);
//该帧属于以接收文件的部分(若讨论文件接收完毕，到短帧中处理)
if (filepool.ContainsKey(packetnum))
{
FileItem fitemp = (FileItem)filepool[packetnum];
byte[] lastfiledata = fitemp.filedata;
byte[] datatemp = new byte[datalen + lastfiledata.Length];
Array.Copy(lastfiledata, 0, datatemp, 0, lastfiledata.Length);
Array.Copy(recvdata, 0, datatemp, lastfiledata.Length, datalen);
fitemp.Index += (ushort)datalen;
fitemp.filedata = datatemp;
filepool[packetnum] = fitemp;
}
//该帧是要传送文件的第一帧，要重新建立缓冲
else
{
FileItem fitemp = new FileItem();
fitemp.filename = sender.filename;
fitemp.filedata = recvdata;
fitemp.Index += (ushort)datalen;
filepool.Add(packetnum, fitemp);
}
}
donerecvinmen = datalen;
error = statecode;
}
break;
//短帧(分类处理，错误和不错误 文件传输结束)
case 0:
{
recvdata = ((PrepareData.Msg_Bus)ByteStruct.BytesToStruct(b_recvframe,
typeof(PrepareData.Msg_Bus))).data;
int count = ((PrepareData.Msg_Bus)ByteStruct.BytesToStruct(b_recvframe,
typeof(PrepareData.Msg_Bus))).dataLen;
datalen = count - 2;
Array.Copy(recvdata, 0, _statecode, 0, 2);
statecode = BitConverter.ToUInt16(_statecode, 0);
//传回的文件不存在错误
if (0 == statecode)
{
if (datalen > 0)
{
filedata = new byte[datalen];
Array.Copy(recvdata, 2, filedata, 0, datalen);
//byte packetnum = hdtr.packetnum;
//ReadFile.Parameter sender = (ReadFile.Parameter)Define.index_obj[packetnum];
//该帧属于以接收文件的部分(若讨论文件接收完毕，到短帧中处理)
if (filepool.ContainsKey(packetnum))
{
FileItem fitemp = (FileItem)filepool[packetnum];
byte[] lastfiledata = fitemp.filedata;
byte[] datatemp = new byte[datalen + lastfiledata.Length];
Array.Copy(lastfiledata, 0, datatemp, 0, lastfiledata.Length);
Array.Copy(recvdata, 0, datatemp, lastfiledata.Length, datalen);
fitemp.filedata = datatemp;
fitemp.Index += (ushort)datalen;
filepool[packetnum] = fitemp;
}
//该帧是要传送文件的第一帧，要重新建立缓冲
else
{
FileItem fitemp = new FileItem();
fitemp.filename = sender.filename;
fitemp.filedata = recvdata;
fitemp.Index += (ushort)datalen;
filepool.Add(packetnum, fitemp);
}
}
//errorcode和datalen都为0，文件传输结束帧
else
{
//不论存在还是不存在都使用create模式，如果文件存在那么就直接覆盖
string filename = sender.filename.ToString();
string path = "d:\\ " + filename + ".txt";
//如果指定位置已经存在该文件
if (File.Exists(path))
{
//MessageBox.Show("接收到的文件已存在，正在准备覆盖源文件！");
}
FileItem fitemp = (FileItem)filepool[hdtr.packetnum];
byte[] lastfiledata = fitemp.filedata;
FileStream tempfile = new FileStream(path, FileMode.Create, FileAccess.Write);
tempfile.Write(lastfiledata, 0, lastfiledata.Length);
tempfile.Flush();
tempfile.Close();
}
}
donerecvinmen = datalen;
//传回的文件存在错误
error = statecode;
}
break;
//错误情况
default:
{
//MessageBox.Show("读文件（msghandle）：长短帧判断处理失败！返回值均为操作！");
}
break;
}
return(donerecvinmen);
}