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From: Alain Dekker on 23 Feb 2010 06:49
I'm using GetTickCount exported from kernel32.dll as follows:
Private Declare Function GetTickCount Lib "kernel32 as Long ' Taken from
several web sources

I'm curious. Why is the type Long (64-bit, signed)? All my previous
compilers (Delphi 7, Visual C++ 6, Visual C++ in VS2003.NET) have returned a
DWORD (unsigned 32-bit number).

The MSDN documentation states that:
DWORD WINAPI GetTickCount(void);
http://msdn.microsoft.com/en-us/library/ms724408(VS.85).aspx

Questions:
* Why does VB return a signed 64-bit number?
* Why doesn't VB have a unsigned 32-bit integer data type anyway? Its got a
8-bit and 16-bit unsigned type, but no 32-bit unsigned.
* What are the units of the VB GetTickCount version? Normally its ms, but
the numbers being returned don't seem to support that.
* Is the VB.NET version somehow more "accurate" or just the way it is
because of the missing unsigned 32-bit integer data type?

Thanks,
Alain


From: Wilson, Phil on 23 Feb 2010 13:22
Inline......from my experience with it.
--
Phil Wilson
The Definitive Guide to Windows Installer
http://www.apress.com/book/view/1590592972


"Alain Dekker" <abdekker(a)NOSPAM.fsmail.net> wrote in message
news:%23NOTl5HtKHA.712(a)TK2MSFTNGP04.phx.gbl...
> I'm using GetTickCount exported from kernel32.dll as follows:
> Private Declare Function GetTickCount Lib "kernel32 as Long ' Taken
> from several web sources
>
> I'm curious. Why is the type Long (64-bit, signed)? All my previous
> compilers (Delphi 7, Visual C++ 6, Visual C++ in VS2003.NET) have returned
> a DWORD (unsigned 32-bit number).

[[ Wraparound is a classic issue with this. Nobody wants to see it suddenly
become zero, as the docs mention. That's in the docs.]]
>
> The MSDN documentation states that:
> DWORD WINAPI GetTickCount(void);
> http://msdn.microsoft.com/en-us/library/ms724408(VS.85).aspx
>
> Questions:
> * Why does VB return a signed 64-bit number?

[[ Which VB? Maybe the one that calls GetTickCount64? ]]

> * Why doesn't VB have a unsigned 32-bit integer data type anyway? Its got
> a 8-bit and 16-bit unsigned type, but no 32-bit unsigned.

[[ No idea. That's VB question. ]]

> * What are the units of the VB GetTickCount version? Normally its ms, but
> the numbers being returned don't seem to support that.

[[ It's best just to treat it as a number. If you want to time things there
are other ways. The docs mention resolution.]]

> * Is the VB.NET version somehow more "accurate" or just the way it is
> because of the missing unsigned 32-bit integer data type?

[[ I'd look at the code and see what it calls. It's just an incementing
integer, there's no accuracy involved, just bigger values. ]]
>
> Thanks,
> Alain
>

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