C#

cant send file bigger that 1 megabit ( Server_client )

        private byte[] GetFileInfo(string fname, string fext, long fsize)
        {
// i was not attention to this Code
// The problem was from here 1024 ,i changed it to 102400000 now correctly working thanks
            byte[] data = new byte[1024];//<--
            byte[] type = Encoding.UTF8.GetBytes("fff");

            byte[] ext = Encoding.UTF8.GetBytes(fext);
            byte[] extE = Encoding.UTF8.GetBytes(":");

            byte[] sizeS = Encoding.UTF8.GetBytes(fsize.ToString());
            byte[] sizeE = Encoding.UTF8.GetBytes("s");

            byte[] name = Encoding.UTF8.GetBytes(fname);
            byte[] nameE = Encoding.UTF8.GetBytes("?");

            Array.Copy(type, data, type.Length);
            Array.Copy(ext, 0, data, type.Length, ext.Length);
            Array.Copy(extE, 0, data, ext.Length + type.Length, extE.Length);
            Array.Copy(sizeS, 0, data, ext.Length + type.Length + extE.Length, sizeS.Length);
            Array.Copy(sizeE, 0, data, ext.Length + type.Length + extE.Length + sizeS.Length, sizeE.Length);
            Array.Copy(name, 0, data, ext.Length + type.Length + extE.Length + sizeS.Length + sizeE.Length, name.Length);
            Array.Copy(nameE, 0, data, ext.Length + type.Length + extE.Length + sizeS.Length + sizeE.Length + name.Length, nameE.Length);
            byte[] newdata = new byte[ext.Length + extE.Length + sizeS.Length + sizeE.Length + name.Length + nameE.Length + type.Length];
            Array.Copy(data, newdata, newdata.Length);
            return newdata;
        }
        private byte[] GetBinaryFile(string filename)
        {
            byte[] bytes;
            using (FileStream file = new FileStream(filename, FileMode.Open, FileAccess.Read))
            {
                bytes = new byte[file.Length];
                file.Read(bytes, 0, (int)file.Length);
            }
            return bytes;
        }
    }
}

for (int i = 0; i < availableComPorts.Length; i++)
{
    try
    {
        string temp = "(" + availableComPorts[i] + ")";
        foreach (ManagementObject queryObj in searcher.Get())
        {
            if ((queryObj["Name"] != null) && (queryObj["Name"].ToString().EndsWith(temp)))
            {
                ComPortInfo comPortsInfo = new ComPortInfo();
                comPortsInfo.officalName             = availableComPorts[i];
                comPortsInfo.userfriendlyDescription = queryObj["Caption"].ToString().Replace("(" + availableComPorts[i] + ")", "").Trim();
                comPortsInfo.manufacturer            = queryObj["Manufacturer"].ToString();
                comPortInfoArrayList.Add(comPortsInfo);
            }
        }
    }
    catch (Exception)
    {
    }
}

_Return_type_success_(return != 0) BOOL CEnumerateSerial::QueryRegistryPortName(_In_ ATL::CRegKey& deviceKey, _Out_ int& nPort)
{
  //What will be the return value from the method (assume the worst)
  BOOL bAdded = FALSE;

  //Read in the name of the port
  LPTSTR pszPortName = nullptr;
  if (RegQueryValueString(deviceKey, _T("PortName"), pszPortName))
  {
    //If it looks like "COMX" then
    //add it to the array which will be returned
    const size_t nLen = _tcslen(pszPortName);
    if (nLen > 3)
    {
      if ((_tcsnicmp(pszPortName, _T("COM"), 3) == 0) && IsNumeric((pszPortName + 3), FALSE))
      {
        //Work out the port number
        nPort = _ttoi(pszPortName + 3);

        bAdded = TRUE;
      }
    }
    LocalFree(pszPortName);
  }

  return bAdded;
}


_Return_type_success_(return != 0) BOOL CEnumerateSerial::QueryUsingSetupAPI(const GUID& guid, _In_ DWORD dwFlags, _Inout_ CPortsArray& ports, _Inout_ CNamesArray& friendlyNames)
{
  //Set our output parameters to sane defaults
#ifndef CENUMERATESERIAL_MFC_EXTENSIONS
  ports.clear();
  friendlyNames.clear();
#else
  ports.RemoveAll();
  friendlyNames.RemoveAll();
#endif //#ifndef CENUMERATESERIAL_MFC_EXTENSIONS

  //Create a "device information set" for the specified GUID
  HDEVINFO hDevInfoSet = SetupDiGetClassDevs(&guid, nullptr, nullptr, dwFlags);
  if (hDevInfoSet == INVALID_HANDLE_VALUE)
    return FALSE;

  //Finally do the enumeration
  BOOL bMoreItems = TRUE;
  int nIndex = 0;
  SP_DEVINFO_DATA devInfo = { 0 };
  while (bMoreItems)
  {
    //Enumerate the current device
    devInfo.cbSize = sizeof(SP_DEVINFO_DATA);
    bMoreItems = SetupDiEnumDeviceInfo(hDevInfoSet, nIndex, &devInfo);
    if (bMoreItems)
    {
      //Did we find a serial port for this device
      BOOL bAdded = FALSE;

      //Get the registry key which stores the ports settings
      ATL::CRegKey deviceKey;
      deviceKey.Attach(SetupDiOpenDevRegKey(hDevInfoSet, &devInfo, DICS_FLAG_GLOBAL, 0, DIREG_DEV, KEY_QUERY_VALUE));
      if (deviceKey != INVALID_HANDLE_VALUE)
      {
        int nPort = 0;
        if (QueryRegistryPortName(deviceKey, nPort))
        {
        #ifndef CENUMERATESERIAL_MFC_EXTENSIONS
          ports.push_back(nPort);
        #else
          ports.Add(nPort);
        #endif //#ifndef CENUMERATESERIAL_MFC_EXTENSIONS
          bAdded = TRUE;
        }
      }

      //If the port was a serial port, then also try to get its friendly name
      if (bAdded)
      {
        ATL::CHeapPtr<BYTE> byFriendlyName;
        if (QueryDeviceDescription(hDevInfoSet, devInfo, byFriendlyName))
        {
        #ifndef CENUMERATESERIAL_MFC_EXTENSIONS
          friendlyNames.push_back(reinterpret_cast<LPCTSTR>(byFriendlyName.m_pData));
        #else
          friendlyNames.Add(reinterpret_cast<LPCTSTR>(byFriendlyName.m_pData));
        #endif //#ifndef CENUMERATESERIAL_MFC_EXTENSIONS
        }
        else
        {
        #ifndef CENUMERATESERIAL_MFC_EXTENSIONS
          friendlyNames.push_back(_T(""));
        #else
          friendlyNames.Add(_T(""));
        #endif //#ifndef CENUMERATESERIAL_MFC_EXTENSIONS
        }
      }
    }

    ++nIndex;
  }

[DllImport("setupapi.dll", CharSet = CharSet.Auto)]
static extern IntPtr SetupDiGetClassDevs(
   ref Guid ClassGuid,
   [MarshalAs(UnmanagedType.LPTStr)] string Enumerator,
   IntPtr hwndParent,
   uint Flags);

[StructLayout(LayoutKind.Sequential)]
struct SP_DEVINFO_DATA
{
    public UInt32 cbSize;
    public Guid ClassGuid;
    public UInt32 DevInst;
    public IntPtr Reserved;
}

[DllImport("setupapi.dll", SetLastError = true)]
static extern bool SetupDiEnumDeviceInfo(IntPtr DeviceInfoSet,
                                         uint MemberIndex,
                                         ref SP_DEVINFO_DATA DeviceInfoData);