public CommBase.PortStatus IsPortAvailable(string s)
{
IntPtr intPtr = Win32Com.CreateFile(s, 0xc0000000, 0, IntPtr.Zero, 3, 0x40000000, IntPtr.Zero);
if (intPtr == (IntPtr)(-1))
{
if ((long)Marshal.GetLastWin32Error() != (long)5)
{
intPtr = Win32Com.CreateFile(this.AltName(s), 0xc0000000, 0, IntPtr.Zero, 3, 0x40000000, IntPtr.Zero);
if (intPtr == (IntPtr)(-1))
{
if ((long)Marshal.GetLastWin32Error() != (long)5)
{
return(CommBase.PortStatus.absent);
}
else
{
return(CommBase.PortStatus.unavailable);
}
}
}
else
{
return(CommBase.PortStatus.unavailable);
}
}
Win32Com.CloseHandle(intPtr);
return(CommBase.PortStatus.available);
}
private void InternalClose()
{
Win32Com.CancelIo(this.hPort);
if (this.rxThread != null)
{
this.rxThread.Abort();
this.rxThread.Join(100);
this.rxThread = null;
}
Win32Com.CloseHandle(this.hPort);
if (this.ptrUWO != IntPtr.Zero)
{
Marshal.FreeHGlobal(this.ptrUWO);
}
this.stateRTS = 2;
this.stateDTR = 2;
this.stateBRK = 2;
this.online = false;
}