C#下调用JustinIO的串口通信问题

运用JustinIO做和串口通信的程序过程中遇到两大问题：

1）SetCommState 一直不成功；

if (!SetCommState(hComm, ref dcbCommPort))
{
uint ErrorNum=GetLastError();
throw (new ApplicationException("Comm Port Can Not Be Opened2"));
}

2）在打开串口后关闭串口，下一次再打开串口出现错误。

两个问题一一得到解决。
一、 针对第1)个问题，是因为结构体public struct DCB 中的一部分被注释了，需要去除注释得到。

        public struct DCB
        {
            //taken from c struct in platform sdk 
            public int DCBlength;           // sizeof(DCB) 
            public int BaudRate;            // current baud rate
            /* these are the c struct bit fields, bit twiddle flag to set */
            public int fBinary;          // binary mode, no EOF check 
            public int fParity;          // enable parity checking 
            public int fOutxCtsFlow;      // CTS output flow control 
            public int fOutxDsrFlow;      // DSR output flow control 
            public int fDtrControl;       // DTR flow control type 
            public int fDsrSensitivity;   // DSR sensitivity 
            public int fTXContinueOnXoff; // XOFF continues Tx 
            public int fOutX;          // XON/XOFF out flow control 
            public int fInX;           // XON/XOFF in flow control 
            public int fErrorChar;     // enable error replacement 
            public int fNull;          // enable null stripping 
            public int fRtsControl;     // RTS flow control 
            public int fAbortOnError;   // abort on error 
            public int fDummy2;        // reserved 
            
            public uint flags;
            public ushort wReserved;          // not currently used 
            public ushort XonLim;             // transmit XON threshold 
            public ushort XoffLim;            // transmit XOFF threshold 
            public byte ByteSize;           // number of bits/byte, 4-8 
            public byte Parity;             // 0-4=no,odd,even,mark,space 
            public byte StopBits;           // 0,1,2 = 1, 1.5, 2 
            public char XonChar;            // Tx and Rx XON character 
            public char XoffChar;           // Tx and Rx XOFF character 
            public char ErrorChar;          // error replacement character 
            public char EofChar;            // end of input character 
            public char EvtChar;            // received event character 
            public ushort wReserved1;         // reserved; do not use 
        }

二 、 针对2）个问题因为JustinIO的 close函数不够完善，在关闭后没有将 opened 从TRUE 变为FALSE。

   public void Close()
        {
            if (hComm != INVALID_HANDLE_VALUE)
            {
                CloseHandle(hComm);
                Opened = false;
            }
        }