Re: Open port USB with vb.net in PDA | Abrir el puerto USB con vb.net en PDA

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From: Sean Gahan (sean_at_optistreams.net)
Date: 04/27/04 

Date: Tue, 27 Apr 2004 15:32:28 -0700

I didn't think that you cant use WriteFile() on a printer port with the NT
kernel, but is this ok with USB?

Regards,

Sean Gahan

"Slobodan Brcin (eMVP)" <sbrcin@ptt.yu> wrote in message
news:ejS%23H2JLEHA.3904@TK2MSFTNGP09.phx.gbl...
> API functions usually won't throw exceptions.
> Assuming that your CreateFile is successful and you have obtained valid
> handle.
>
> WriteFile function will work. Or at least it worked on all USB COM ports I
> have used so far.
>
> I fail to see what DeviceIoControl code you have tried to use.
>
> BTW: make sure that GetLastError function returns 0 in all cases after
each
> function you call.
>
>
> Regards,
> Slobodan
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Have an opinion on the effectiveness of Microsoft Embedded newsgroups?
Tell
> Microsoft!
> https://www.windowsembeddedeval.com/community/newsgroups
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> "Edgar Hdz" <ragdeh@hotmail.com> wrote in message
> news:#0pLefJLEHA.1484@tk2msftngp13.phx.gbl...
> > Thanks Slobodan
> >
> > But, my code don't return error or Exception code;
> > I use GetLastError() and all Ok,
> > At this moment I can open the COM9 but now I need to send text to USB
port
> > for RS232
> > I use WriteFile() and it doesn't send nothing or even return error or
> > exception code
> > I also use DeviceIOcontrol() and it doesn't send nothing or even return
> > error or exception code
> >
> > can you help me?
> >
> > I need a number for IOCTL_XXXXX maybe you can send it with them !
> >
> > Thanks
> > Edgar Hdz
> >
> > |<Español>|
> > Gracias Slobodan
> >
> > Pero mi codigo no regresa codigo de error o excepción;
> > uso GetLastError() y todo funciona,
> > en este momento he logrado abrir el puerto COM9 pero ahora necesito
> enviarle
> > datos a el puerto para RS232
> > uso WriteFile() y no envia nada ni regresa codigo de error o excepción
> > tambien uso DeviceIOcontrol() y no envia nada ni regresa codigo de
error
> o
> > excepción
> >
> > Puede ayudarme?
> >
> > Necesito los numeros para IOCTL_XXXXX quizá pueda enviarlo con esto!
> >
> > Gracias
> > Edgar Hdz
> >
> >
> >
> >
> >
> > "Slobodan Brcin (eMVP)" <sbrcin@ptt.yu> escribió en el mensaje
> > news:uKFcaFJLEHA.1272@tk2msftngp13.phx.gbl...
> > > Edgar this is probably wrong NG.
> > >
> > > You should check errors returned by CreateFile and other functions.
> > >
> > > Use GetLastError to get error code.
> > > Without this error code there is a little that we can do to help you.
> > >
> > > BTW: In case that open fails on COM9: try \\.\COM9:
> > >
> > > Regards,
> > > Slobodan
> > >
> > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > Have an opinion on the effectiveness of Microsoft Embedded newsgroups?
> > Tell
> > > Microsoft!
> > > https://www.windowsembeddedeval.com/community/newsgroups
> > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > >
> > > "Edgar Hdz" <ragdeh@hotmail.com> wrote in message
> > > news:utXtUAJLEHA.1644@TK2MSFTNGP09.phx.gbl...
> > > > Hi everybody |<es>| Hola a todos
> > > >
> > > > I have a problem with a USB; I can´t open USB port with VB.net for
PDA
> > > > |<es>| Tengo un problema con el USB; no he logrado abrir el puerto
USB
> > con
> > > > VB.net
> > > >
> > > > I need send text to a printer RS232 but i can´t;
> > > > |<es>| Necesito enviar texto a una impresora RS232 pero no puedo
> > > > I have USB to RS232 (Chip PL2303)
> > > > |<es>| Tengo un cable USB a RS232 (Chip PL2303)
> > > >
> > > > can you help me? can you tell me how open the port?
> > > > |<es>| Prodrian ayudarme? podrian decirme como abrir el puerto?
> > > >
> > > > I use CreateFile() and WriteFile() but it dosen't works
> > > > |<es>| He usado CreateFile() y WriteFile() pero no funcina
> > > >
> > > > I also use CreateFile() and DeviceIOcontrol() but it dosen't works
> > > > |<es>| Tambien he usado CreateFile() y DeviceIOcontrol() y no
funciona
> > > >
> > > >
> > > > Example Code
> > > >
> > > > <DllImport("coredll.dll")> _
> > > > Private Shared Function CreateFile(ByVal lpFileName As String, _
> > > > ByVal dwDesiredAccess As Integer, ByVal dwShareMode As
> Integer,
> > _
> > > > ByVal lpSecurityAttributes As Integer, ByVal
> > dwCreationDisposition
> > > > As Integer, _
> > > > ByVal dwFlagsAndAttributes As Integer, ByVal hTemplateFile
As
> > > > Integer) As Integer
> > > > End Function
> > > > <DllImport("coredll.dll")> _
> > > > Private Shared Function DeviceIoControl( _
> > > > ByVal hDevice As Int32, ByVal dwIoControlCode As Int32,
_
> > > > ByRef lpInBuffer As Int32, ByVal nInBufferSize As Int32,
_
> > > > ByRef lpOutBuffer As String, ByVal nOutBufferSize As
> Int32,
> > _
> > > > ByRef lpBytesReturned As Int32, ByRef lpOverlapped As
> > Int32)
> > > As
> > > > Int32
> > > > End Function
> > > > <DllImport("coredll.dll")> _
> > > > Private Shared Function WriteFile( _
> > > > ByVal hFile As Int32, ByVal Buffer As Byte(), ByVal
> > > > nNumberOfBytesToWrite As Int32, _
> > > > ByVal lpNumberOfBytesWritten As Int32, ByVal overlapped As
> > Int32)
> > > > As Int32
> > > > End Function
> > > >
> > > > Function PrinterDeviceIO()
> > > > idPort = CreateFile("COM9:", GENERIC_READ Or GENERIC_WRITE, 0,
0,
> > > > OPEN_EXISTING, 0, 0)
> > > >
> > > > intBF = DeviceIoControl(idPort, FILE_GENERIC_WRITE, 2048, 1,
> > > > strValue, strValue.Length, intReturn, intOver)
> > > > End Function
> > > >
> > > > Function PrinterWriter()
> > > > idPort = CreateFile("COM9:", GENERIC_READ Or GENERIC_WRITE, 0,
0,
> > > > OPEN_EXISTING, 0, 0)
> > > >
> > > > intBF = WriteFile(idPort, bytBuffer, bytBuffer.Length, 1024, 0)
> > > > End Function
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>

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