Debugging DLLs

[Azrael-TFX-]

I'm working on a plugin system, and I'd like to be able to debug my plugin dll's as I work on them. Problem is, to use them they have to be compiled into actvex dlls, which are then referenced and loaded at runtime by the main program.

Is there any way of pausing exection of the program to see what's going on inside the dll?

Thanks,
Az.

[radum]

you can open multiple projects in your vb6 gui inside a 'project group'. open the client exe, then File -> Add Project your dll server. you will have simultaneous debugging capabilities.

[Azrael-TFX-]

Yeah I know that, but because it's loading a built dll, which is having it's references added at runtime, it won't jump back into VB to debug it.

[radum]

ammm... nope. there may be no easy way to do the debugging in your case. sorry i took you for a beginner.

[brucevde]

How are you creating an instance of your plugin dll in your client?

If you are using CreateObject then this code

Dim objTemp As Object

Set objTemp = CreateObject("Plugin.Testing")
objTemp.ProcessIt

Set objTemp = Nothing

whether in a compiled app or a second instance of VB - will stop at any breakpoint and allow you to debug the Plugin dll, as long as it also is currently executing in VB. SOP.

[Azrael-TFX-]

The problem is, the app is loading the dll by finding it on disk, rather than looking in the registry to find it, so the plugin has to be built as the dll for the main app to load it. This means that it can't be running in vb since it must be compiled and on disk.

You may be right radum, there may be no way for me to debug them like this I might have to build an extra function in my main program to load a plugin that's not been built yet (ie still in the vb environment) just to debug them.

[si_the_geek]

The problem is, the app is loading the dll by finding it on disk, rather than looking in the registry to find it, so the plugin has to be built as the dll for the main app to load it. This means that it can't be running in vb since it must be compiled and on disk.

So why don't you add an extra line of code which says "if this program is being run from VB, just load the DLL without searching for it"

eg:

'...
If RunningInVB Then
  'use "createobject" to load the DLL
Else
  'search for the dll as you do already
End If
'...
 
Function RunningInVB() As Boolean
'Returns whether we are running in vb(true), or compiled (false)
 
    Static counter As Variant
    If IsEmpty(counter) Then
        counter = 1
        Debug.Assert RunningInVB() Or True
        counter = counter - 1
    ElseIf counter = 1 Then
        counter = 0
    End If
    RunningInVB = counter
 
End Function

[Azrael-TFX-]

That might help us to be able to write and debug our own plugins, since we can run the main app in vb, but for other people who want to write plugins for it, they'll be a bit stuck without our source code

[si_the_geek]

well in that case, you could add a command line parameter for debugging, that specifies the name used for the "createobject" call.

[Azrael-TFX-]

Originally posted by Azrael-TFX-
You may be right radum, there may be no way for me to debug them like this I might have to build an extra function in my main program to load a plugin that's not been built yet (ie still in the vb environment) just to debug them.

I already said that

Thanks guys, think I'll try adding another function in the app

[Azrael-TFX-]

Ok, I've added another function, and the main exe finds and loads the plugin from the vb environment, but my problem now is I'm trying to pass an object into the plugin, and getting this error:

Run-time error '98':

A property or method call cannot include a reference to a private object, either as an argument or as a return value.


What I'm trying to do works fine when I load a plugin from the dll, but it doesn't want to pass the object across from the exe to a plugin that's running in the vb environment. Is there any way to give my plugin access to this object?