How to determine clicking the What's This Button on a form ?

[Michael Hartmann]

Hello everybody,

I need your help. I need the ability to determine when the "What' this" button on a form is clicked. I think i have to subclass my form and look for the right message. Could anybody tell me what message I have to look for.

Best regards

Michael Hartmann

[Lothar Haensler]

if your form is a dialog, you can set the WhatsThisButton property to true.
Then simply set the WhatsThisHelpID of your controls to the Topic ID in your help file.
no need for subclassing.

[Michael Hartmann]

I think the problem I described was misunderstood. I don't have problems implementing a "What's this" help in a VB6 program. The problem is the following:
We have two different helpfiles for the application. One with the topics of the "What's This" help and one normal helpfile which is called by pressing F1. No we have added links into the topics of the "What's this" help to topics in the regular helpfile. First time you click on such a link the regular helpfile starts with the correct topic. Now, when you leave the regular help open and click on another (or the same) link a "What's This" help topic the program couldn't find the regular helpfile (maybe problem by MS). After this error, the regular helpfile will be closed. Now you can click on a link without been trapped by this error. Now what I want to do is, when the user clicks on the little button with the question mark I want to kill the regular help file with the API function "TerminateProcess". I looked with Spy++ what message will be send when a user clicks on this button. I subclassed my form and looked exactly for this message to do this. But, to my surprise, this message wasn't send anymore (very mysterious). So I want to know if anybody know what message was send my MS to switch the cursor in "What's this" help mode. Another problem is getting the ID of the process where the helpfile will be started after clicking a link in a "What's This" help topic. I hope anybody as a very good idea, I think this will be very complex problem.

Best regards

Michael Hartmann