Hello everyone!

I've just finished the tutorial on how to let a DLL, which is Interop.Call()ed by scripts, interface with Plus! scripting objects.

This tutorial guides script developers to have their native Win32 DLLs manipulate scripting objects (MsgPlus, Messenger, ChatWnd, Contact, PlusWnd, ...) as in JScript. We know that DLLs are crucial to implement asynchronous callbacks, which are in term crucial to subclassing non-Plus! windows (aside from machine-code-injection). However, before this tutorial, it was never (I think) disclosed how DLLs can interact with scripting objects in their native C++ codes. This is also the very technique that enables HopperLive to change Messenger's status and create a PlusWnd in its DLL.

If you're interested, please take a look! And tell me what you think about it, especially if you feel something is left unsaid, is not clear, or if you want more detail on specific topics. Requests for specific examples are welcome too!

Happy reading!

Nice one! Thanks for sharing.

Bookmarked! I have yet to find a script project where I need to use an extra DLL to do what I need, but if I do I now have a place to start.

Thank you for this excellent write-up!

Wow, excellent written tut .....

Nice one

Btw, shouldn't this one be sticky?

It is half stickied: http://shoutbox.menthix.net/important.php

Hello folks,

I've updated the tutorial, briefing on how to let the DLL call back JScript function. It's in the tutorial's last section under the name of Advanced Topics. Special thanks to Eljay for shedding some light on the mechanism!

Ref: C# DllExportAttribute.

Okay, I've got absolutely no idea how the above thingy supposed to work, but can this tutorial be applied to C# as well?

quote:

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Originally posted by SmokingCookie
Ref: C# DllExportAttribute.

Okay, I've got absolutely no idea how the above thingy supposed to work, but can this tutorial be applied to C# as well?

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I remember that regasm has some command-line argument that exports a .tlb file; could that be what you're pointing at?

Doesn't Patchou have anything like a .tlb file?

The TLB is already in MsgPlusLive.dll as a resource (resource type TYPELIB\1). You just need to extract it. You can extract type libraries resources (TLB files) in various ways.

You can use rundll32.exe for example to extract it (although it is not straitforward; also, instead of the keyword 'TypeLib' you could use 'GenerateTypeLib')

Or from Microsoft: The OLE/COM Object Viewer can extract the IDL (decompiled Type Library).
(File > View TypeLib > select MsgPlusLive.dll)

More tools from Microsoft:
http://msdn.microsoft.com/en-us/library/ms680581(VS.85).aspx

Or you can use tools like Resource Hacker or (even better, but not free) PE Explorer to extract the compiled type library.

Then there are Type Library viewers like TypeLib Viewer from iTripoli.

Note that RegAsm.exe  isn't going to work here.


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I recommend using Resource Hacker (free) or PE Explorer (can be used for 30 days for free). Using PE explorer is the easiest way to extract a TLB imho.

In Resource Hacker:
- Open MsgPlusLive.dll
- Select the TYPELIB\1\0 resource
- From the Action menu, choose 'Save Resource as a binary file' or 'Save Resource as a *.res file'
- Rename the saved file to "MPLiveScriptingLib.tlb"

In PE Explorer:
- Open MsgPlusLive.dll
- Go to the resource viewer
- Right click on the TYPELIB\1 resource
- Choose 'Save Resource as...' (or click CTRL+SHIFT+S)
- Enter the filename "MPLiveScriptingLib.tlb"

The super easy way to extract resources, if you have 7-Zip installed, just right-click the .dll and extract with 7-Zip.

Okay, I've got the .tlb file; now what?
Visual Studio won't add a reference to it.

EDIT: I've got it in VS's object browser atm, and it does indeed show the members described by Mnjul.