的串口通讯支持总是让人觉得有所不足在使用VB的MsCommocx时很多人都会在的开发中觉得很困扰
这里讲述的串口通讯类使用native代码并且它是通API调用实现的你会发现的串口通讯就是这么简单
在说明如何使用这个类前需要说明的是本类只是一个的串口通讯演示你可能需要根据你的情况修改后使用另外本类的目的是通过例子教会你在无需ocx控件和第三方组件的支持下用开发串口通讯程序所有并没有完善的异常错误处理
１初始化并打开串口
创建一个CRs类的实例并在调用Open方法前设置好串口通讯参数
例
Dim moRS as New Rs()
With moRs
Port = //Uses COM
BaudRate = //波特率
DataBit = // data bits
StopBit = RsDataStopBitStopBit_//停止位
Parity = RsDataParityParity_None//无奇偶校验
Timeout = //超时时间 ms
End With
// 初始化并打开串口
moRSOpen ()
// 串口打开后你可以随意地控制DTR/RTS
moRSDtr = True
moRSRts = True
为了处理异常情况建议你使用TryCatch
２发送数据
本类为Rx和Tx准备了两个缓沖区(buffer)发送数据时只需要设置TxData属性为你需要发送的数据然后调用Tx方法就可以了
例如
moRSTxData = txtTxText
moRSTx()
接收数据
先调用Rx方法（参数为您需要从串口读取的字节数）然后读取RxData属性
例如
moRSRx() // 从串口通讯缓沖区里读取字节
Dim sRead as String=moRsRxData
需要注意的是当本类无法用串口读取到所需的字节数程序线程在超时异常发生前是锁死的超时时间通过Timout属性设置
如果你没有指明需要读取的字节数本类默认使用字节来读取缓沖区里的数据
版本信息
Project History
st Public release Beta (//)
Rev ()
Added ResetDev SetBreak and ClearBreak to the EscapeCommFunction constants
Added the overloaded Open routine
Added the modem status routines properties and enum
If a read times out it now returns a EndOfStreamException (instead of a simple Exception)
Compiled with VSNet final
Rev ()
Added Async support
Rev ()
Minor bugs fixed
Reva (//)
Fixed BuildCommmDCB problem
Rev (//)
Fixed problem with ASCII Encoding truncating th bit
Rev (//)
Added IDisposable / Finalize implementation
Rev (//)
Fixed problem on DCB fields Initialization
Rev (//)
Added XON/XOFF support
Rev (//)
Added support to COM port number greater than
Rev (//)
Added CommEvent to detect incoming chars/events(!)
Updated both Tx/Rx method from NonOvelapped to Overlapped mode
Removed unused Async methods and other stuff
Rev (//)
Fixed incorrect character handling when using EnableEvents()
Rev (//)
Fixed some bugs reported by users
Rev (//)
Removed AutoReset of internal buffers and added PurgeBuffer() method
Rev (//)
Update internal stuff now using WinException instead of GetLastError+FormatMessage APIs
Rev (//)
Added IsPortAvailable() function (thanks to Tom Lafleur for the hint)
Revised some API declaration
Fixed some problems with Win/Me OS (thanks to Alex Komissarov for the feedback)
Rev (//)
Fixed bug introduced on rev (sorry for that)
Rev (//)
Added SetBreak/ClearBreak methods for sending break signal over the line
Rev (//)
Fixed incorrect field on COMMCONFIG Structure
Rev (//)
Fixed bug causing troubles accessing already in use ports (folks thanks for the feedback!)
Rev (//)
Fixed bug on DTR property (thanks to CharlesOlivier Théroux)
Rev (//)
CommEvent is no more raised on a secondary thread (please note that this is valid only if event handler is not associated with a static method)
pEventsWatcher now uses a background thread
Rev (//)
Fixed EscapeCommFunction declaration
Fixed incorrect Pariti enum entry
Rev (//)
Fixed memory leak causing random program termination without any message
Thanks to Ralf Gedrat for testing this scenario
Rev (//)
Fixed bug DisableEvents not working bug (Thanks to Jean Bédard)
