private SerialPortFixer(string portName)
{
if (portName == null || !portName.StartsWith("COM", StringComparison.OrdinalIgnoreCase))
{
throw new ArgumentException("Invalid Serial Port", nameof(portName));
}
SafeFileHandle file = SerialPortFixer.CreateFile("\\\\.\\" + portName, -1073741824, 0, IntPtr.Zero, 3, 1073741824, IntPtr.Zero);
if (file.IsInvalid)
{
SerialPortFixer.WinIoError();
}
try
{
switch (SerialPortFixer.GetFileType(file))
{
case 0:
case 2:
m_Handle = file;
InitializeDcb();
break;
default:
throw new ArgumentException("Invalid Serial Port", nameof(portName));
}
}
catch
{
file.Close();
m_Handle = null;
throw;
}
}
private static string GetMessage(int errorCode)
{
var lpBuffer = new StringBuilder(512);
if (SerialPortFixer.FormatMessage(12800, new HandleRef(null, IntPtr.Zero), errorCode, 0, lpBuffer, lpBuffer.Capacity, IntPtr.Zero) != 0)
{
return(lpBuffer.ToString());
}
return("Unknown Error");
}
private void SetCommStateNative(ref SerialPortFixer.Dcb lpDcb)
{
var lpErrors = 0;
var lpStat = new SerialPortFixer.Comstat();
for (var index = 0; index < 10; ++index)
{
if (!SerialPortFixer.ClearCommError(m_Handle, ref lpErrors, ref lpStat))
{
SerialPortFixer.WinIoError();
}
if (SerialPortFixer.SetCommState(m_Handle, ref lpDcb))
{
break;
}
if (index == 9)
{
SerialPortFixer.WinIoError();
}
}
}
private static void WinIoError()
{
var lastWin32Error = Marshal.GetLastWin32Error();
throw new IOException(SerialPortFixer.GetMessage(lastWin32Error), SerialPortFixer.MakeHrFromErrorCode(lastWin32Error));
}