C#串口操作(國外網站看來的，共享一下)

前一陣，從國外網站看到一個用C#來操作串口的類。下載下來試了一下，覺得不錯。共享一下。
/*
* Author: Marcus Lorentzon, 2001
* [email protected]
*
* Freeware: Please do not remove this header
*
* File: SerialStream.cs
*
* Description: Implements a Stream for asynchronous
* transfers and COMM. Stream version.
*
* Version: 2.4
*
*/

#region Using

using System;
using System.IO;
using System.Threading;
using System.Runtime.InteropServices;
using System.ComponentModel;

#endregion Using

namespace LoMaN.IO {

public class SerialStream : Stream {

#region Attributes

private IOCompletionCallback m_IOCompletionCallback;
private IntPtr m_hFile = IntPtr.Zero;
private string m_sPort;
private bool m_bRead;
private bool m_bWrite;

#endregion Attributes

#region PropertIEs

public string Port {
get {
return m_sPort;
}
set {
if (m_sPort != value) {
Close();
Open(value);
}
}
}

public override bool CanRead {
get {
return m_bRead;
}
}

public override bool CanWrite {
get {
return m_bWrite;
}
}

public override bool CanSeek {
get {
return false;
}
}

public bool Closed {
get {
return m_hFile.ToInt32() 0;
}
}

public bool Dsr {
get {
uint status;
if (!GetCommModemStatus(m_hFile, out status)) {
throw new Win32Exception();
}
return (status & MS_DSR_ON) > 0;
}
}