mscomm

[onder]

mscomm control for serial port communication is not available in .net
but anyone out there who have used VB6 mscomm control in VB.net via interop?

[Patrick Steele [MVP]]

In article <3dc6a27a$1@tnews.web.devx.com>, oaydogan61@hotmail.com
says...
>
> mscomm control for serial port communication is not available in .net
> but anyone out there who have used VB6 mscomm control in VB.net via interop?

This might get you started. It's C#, but has a lot of explanation:

http://www.devhood.com/tutorials/tut...utorial_id=320

--
Patrick Steele
Microsoft .NET MVP
http://radio.weblogs.com/0110109

[Dick Grier]

Hi,

By far the simplest way is to download NETComm.ocx from my homepage. It is
free, and is designed for this express purpose.

BTW, I have native .NET example code in my book (see below), if you want to
go that way. There also are other .NET examples available online.
Personally, most of these are too limited for me, but that is me.

--
Richard Grier (Microsoft Visual Basic MVP)

See www.hardandsoftware.net for contact information.

Author of Visual Basic Programmer's Guide to Serial Communications, 3rd
Edition ISBN 1-890422-27-4 (391 pages) published February 2002.

[Dick Grier]

Hi Patrick,

Take a look at my reply. Also, for VB types, there is online code at
UsingtheCOMPortinVB.exe (from the VB .NET examples compiled by Mike Iem).

--
Richard Grier (Microsoft Visual Basic MVP)

See www.hardandsoftware.net for contact information.

Author of Visual Basic Programmer's Guide to Serial Communications, 3rd
Edition ISBN 1-890422-27-4 (391 pages) published February 2002.

[onder]

Thank you for the replies.

One question: are there any 'noticable' performance loss due to COM interop
in VB:NET due to this mscomm.ocx usage? ( i don't know if the question makes
sense! )

[Dick Grier]

Hi,

>>
One question: are there any 'noticeable performance loss due to COM interop
in VB:NET due to this mscomm.ocx usage? ( i don't know if the question makes
sense! )
<<

No (Interop does incur some overhead; but the effect is quite small in an
actual app). However... There are performance issues with .NET itself.
Most serial communications applications append data to string buffers. This
operation is much more expensive in .NET (where strings are immutable) than
in earlier versions of VB. The StringBuilder is not often a useful
solution. None-the-less, even this potential problem is not often an issue.

--
Richard Grier (Microsoft Visual Basic MVP)

See www.hardandsoftware.net for contact information.

Author of Visual Basic Programmer's Guide to Serial Communications, 3rd
Edition ISBN 1-890422-27-4 (391 pages) published February 2002.

[onder]

I always hear that VB6 string operations are very slow! it is suprising that
VB.NET strings are slower. Why is stringbuiler not a solution?

"**** Grier" <****_grier@msn.com> wrote:
>Hi,
>
>>>
>One question: are there any 'noticeable performance loss due to COM interop
>in VB:NET due to this mscomm.ocx usage? ( i don't know if the question makes
>sense! )
><<
>
>No (Interop does incur some overhead; but the effect is quite small in an
>actual app). However... There are performance issues with .NET itself.
>Most serial communications applications append data to string buffers.
This
>operation is much more expensive in .NET (where strings are immutable) than
>in earlier versions of VB. The StringBuilder is not often a useful
>solution. None-the-less, even this potential problem is not often an issue.
>
>--
>Richard Grier (Microsoft Visual Basic MVP)
>
>See www.hardandsoftware.net for contact information.
>
>Author of Visual Basic Programmer's Guide to Serial Communications, 3rd
>Edition ISBN 1-890422-27-4 (391 pages) published February 2002.
>
>

[Dick Grier]

Hi,

You have to buffer data (somewhere) before you can use StringBuilder to
append. Well, that buffer often will be a string, which must be created
anyway, with the incumbent overhead. Also, StringBuilder assumes that you
know, in advance, the maximum string lenght. This often is not known.
All-in-all it is a pain.

VB6 strings were not immutable. Thus, they could be appended (to) without
incurring the overhead of creating a new string for every string append (as
in .NET).

--
Richard Grier (Microsoft Visual Basic MVP)

See www.hardandsoftware.net for contact information.

Author of Visual Basic Programmer's Guide to Serial Communications, 3rd
Edition ISBN 1-890422-27-4 (391 pages) published February 2002.