This is somewhat related to a similar post, but that post was Visual Studio 6 in general and a lot of the suggestions didn't apply to VB6.
Suggest or vote for tools/tips. Please one tool/tip per post so that everyone can vote on them individually. Include a brief description of what the tools do.
Matt Curlands Power VB book and the VBoost tools that came with it, especially the Type library editor.
Just watch out for the non-DEP compliant techniques.
I realllly hate checking to see if an array is uninitialized by passing it to a helper function that tries to do a UBound and catches the error if it occurs.
Solution?
Use VarPtr to get the array's address, pass the address to CopyMemory to get the SafeArray structure for the array, if the SafeArray structure indicates 0 dimensions, the array is uninitialized.
EDIT thanks to Lance for good link with example
http://vbnet.mvps.org/index.html?code/helpers/getarraydims.htm
I discovered a lot of things when I was first learning by using the wizards to make forms/small applications, and then examining the code they output.
Design Patterns by the GoF. While it doesn't seem specific for VB6 the fact that most of the patterns are based interface implementation and aggregating objects (as opposed to inheritance) makes it well suited for use with VB6. They talk about this on pages 16 to 18 and sum it up in one statement. Program to an interface, not an implmentation If there is one thing that VB6 and COM does well is handle interfaces.
The entire mvps.org site here
I recommend Karl Peterson' One stop source and Randy Birch's VBnet (which has nothing to do with VB.NET) and Common Controls Replacement Project.
After installing VB6, I always do these customisations on Tools-Options.
Switch off Auto Syntax Check on the Editor tab. You don't want message boxes when you type a syntax error - you just want the problem line shown in red so you can fix it later.
Switch on Require Variable Declaration on the Editor tab. Don't think, just do it.
Switch off Compile On Demand on the General tab. You want to be told about syntax errors immediately when you run your code, not just when the dodgy routine actually gets called.
EDIT: Prompt to save changes when program starts, on the Environment tab. (Thanks wqw for reminding me in the comments.)
Set Error Trapping to "Break on unhandled errors" on the General tab. Actually, this is a personal preference - but you should select the setting that suits you. Hopefully you've worked out an error handling strategy for the VB6 program?
I have an LCD screen, and the default colours don't work very well, so I change them to lighter ones. I'm also using the Consolas font. Makes my VB6 code look twenty-first century anyway :)
I haven't tried this myself yet, but CodeShine is a cheap refactoring add-in for VB6. It can do the useful extract method refactoring, apparently.
I must stop wasting time here and download the free trial to try it out.
VB6 error handling sucks. So I've adopted these patterns to make it easier:
The Try-Catch block:
'Try
On Error Goto catchX
...
'Catch
catchX: if err.number then
...
resume resumX
resumX: end if
On Error Goto outside_catch_label_name
'End Try
Including a stack trace in errors:
sub rethrow(byval source as string)
Err.Source = Err.Source & vbNewLine & vbTab & "@ " & Source
Err.Raise Err.Number, Err.Source, Err.Description
end sub
sub some_sub: on error goto throw
...
throw: if err.number then rethrow("some_sub")
end sub
Check out http://angryhacker.com/blog/archive/2008/05/01/vb6-swiss-army-knife.aspx
It has most tools I use for whenever I have to delve into VB6, plus a description of what they do. In addition to the tools mentioned here, it also has the following:
The vbAdvance add-in is now free.
vbAdvance is a Visual Basic Add-In that gives you access to advanced build features and many IDE convenience features. Create console apps, create standard DLLs that export functions, create a DllMain entry point in your DLLs, XP Manifest compiler for XP styles, Terminal Server, etc.
Make My Manifest can produce Reg-Free COM manifests (chucking in "Styles" as needed, etc.). This allows XCopy deployment of many VB6 EXEs to WinXP or later.
No more "dependency" fears or DLL Hell!
The vbAccelerator website. It has so many great examples and free controls with the full source. The site has not been updates in a few years now, but it still keeps running and I still go back to it when working in VB6.
One great tool that is out there and I've used is called CodeFixer. I believe I first stumbled across CodeFixer here.
It's even open source. I have had a little contact with the author, Roger Gilchrist, and he seems to still be working on it in his, surely limited, free time.
Aivosto's Project Analyzer http://www.aivosto.com/project/project.html
I can't believe no one has yet posted Bruce McKinney's Hardcore Visual Basic (now free online on mvps.org)! OK it's a book rather than a piece of software, but it expands to a veritable cornucopia of tools and tips.
The collection class replacement from Spider Eye called Spider Eye Flexbag is an absolute must. Its 100% better than the collection classes that ship with VB and its blindingly fast compared to the original collections. The Flexbag collection was written by Gary Wisniewski of "Carl 'n Gary's Visual Basic Home Page" fame.
Unfortunately the Spider Eye website doesn't seem to have a link to the Flex Bag at the moment, but I'm sure if you contact them they'd be happy to sort something out for you. If you are doing any collection based work at all then it would be well worth the effort.
The AVE Code Finder is handy because the Find function in the VB6 IDE can't be trusted. AVE Code Finder is also much much faster then the built in Find. It was written by Jarek Zwierz of www.ave.com.pl but the site doesn't seem to exist anymore so the version I've linked to is at VB2TheMax.
The VB6 IDE doesn't remember your preference for maximizing the code windows. To start up with the VB6 code windows maximized, set this string registry key:
[HKEY_CURRENT_USER\Software\Microsoft\Visual Basic\6.0]
"MdiMaximized"="1"
SmartIndenter takes care of all the auto-indenting. It does one thing and it does it really well. And it's free.
http://www.oaltd.co.uk/Indenter/Default.htm
The VB6 Credits Easter Egg that lists the development team :)
To show the VB6 Program Credits create an 'About' button to the standard toolbar and rename its caption to 'Show VB Credits'. Here's a bit more detail: