Intercepting messages from an application I did not write

[Mike Jackson]

We use WinInstall to distribute software. I would like to be able to intercept messages from WinInstall to the system and modify some messages and delete others. I'm not sure if this is possible without knowing and having access to the interworkings of WinInstall. Can I just use a Window Handle to intercept the messages or is it more involved? Any help would be appreciated.

MJ

[MerrionComputin]

You cannot subclass a window that belongs to another process.

You could install a wh_getmessage hook which will get called whenever a message is removed from the message queue of the target application but, as far as I am aware, you cannot modify a message using such a hook.

Alternatively you can attach to the process using a debugger, set a breakpoint on th eapplication's message handler and work from there.

However, all of this is difficult at best.

HTH,
Duncan

[Mike Jackson]

Well, I was afraid of that. WinInstall launches installations of software packages. Sometimes these packages have pre-requisites that get loaded if they are not present. The problem comes in when those pre-requisites are being installed. WinInstall just sits there like it's locked up. What we want to do is to display a dummy progress bar that goes away when the prerequisite is finished installing.

If I could launch the prerequisite install in one process and my progress bar in another process so that they ran simultaneously then that would solve my problem. If I used the hook you referred to, would I be able to detect when the prerequisite finished?

MJ