Hi,

I have got an old VB 3 Application in combination with an Access 1.1
Database. My ambitious plan is now to port the application on the actual VB
Version 6 and extend it with some new functionalities . But keep the changes
on the old code minimaly as possible. I am not sure to upgrade the database
engine, too.

My questions are:

How can I port the application ?

Are there tools available ?

What are the typical problems ?

What problems does occur if I change the database engine to e.g. Access 97 ?
Or vice versa what problems occour if I use Access 1.1 in future ?

Where can I find further information regardig this topic ?

The Application uses following 16 Bit VBX Controls

cmdialog, crystal, graph, grid, threed

Wich of them could cause problems ?

There are also same API calls used. The application works fine under Win98
and Win2000. So I guess that I will get no problems with the API Calls with
VB6. Is that right ?

thank you for assitance

Daniel

See the VB 3 page at http://www.gridlinx.com
You can get a copy of the free Crescent Upgrade Wizard there.
...
George
GridLinx Software    Programming Tools for VB Programmers

<snip>

First, save everything from VB 3 *as text*.

By default, VB3 uses a binary file format that current
versions can't read.

I believe Sheridan has an upgrade wizard.

API calls are changed, controls are changed, the
language has changed....

...stuff like that.

After VB 3, VB automatically coerces data into the
type required by the statement; VB 3 code that
depends on receiving a "Type Mismatch" error can
fail.

Read the MSDN periodicals documentation on "Evil
Type Coercion" for some of the pitfalls.

?

A lot has changed. The object structure is different,
methods were removed and changed.

I don't think that is an option. I believe the earliest
Access engine supported by VB 32 bit is 2.5,
via a compatibility driver.

The MSDN documentation, VB Programmer's
Journal back issues.

Common dialog, Crystal, and Threed are still there,
and largely unchanged (as far as backward compatibility
goes). Graph is there, but I believe there were
changes. Grid has been replaced; I believe the stock
control is a version of the Apex grid control.

Any or all of them.

No, that's wrong. 32 bit APIs are very different in
some ways than the 16 bit ones. You *will* rewrite
almost all declare statements; you probably will
need to find 32 bit replacements for 16 bit API
calls; you *may* not be able to do things in the
same way at all.

Expect to do some real work.

<snip>

First, save everything from VB 3 *as text*.

By default, VB3 uses a binary file format that current
versions can't read.

I believe Sheridan has an upgrade wizard.

API calls are changed, controls are changed, the
language has changed....

...stuff like that.

After VB 3, VB automatically coerces data into the
type required by the statement; VB 3 code that
depends on receiving a "Type Mismatch" error can
fail.

Read the MSDN periodicals documentation on "Evil
Type Coercion" for some of the pitfalls.

?

A lot has changed. The object structure is different,
methods were removed and changed.

I don't think that is an option. I believe the earliest
Access engine supported by VB 32 bit is 2.5,
via a compatibility driver.

The MSDN documentation, VB Programmer's
Journal back issues.

Common dialog, Crystal, and Threed are still there,
and largely unchanged (as far as backward compatibility
goes). Graph is there, but I believe there were
changes. Grid has been replaced; I believe the stock
control is a version of the Apex grid control.

Any or all of them.

No, that's wrong. 32 bit APIs are very different in
some ways than the 16 bit ones. You *will* rewrite
almost all declare statements; you probably will
need to find 32 bit replacements for 16 bit API
calls; you *may* not be able to do things in the
same way at all.

Expect to do some real work.