Solved

How do I use CDialog::PreTranslateMessage() in 16-bit?

Posted on 1997-06-13
9
447 Views
Last Modified: 2013-12-03
How can I get my dialog (derived from CDialog) to respond to the PreTranslateMessage.  I can do it with no problems in 32-bit, but in 16-bit, the same function never gets called.
I'm trying to use this to capture the keyboard input before it gets to an edit box (which has the focus).
0
Comment
Question by:postrowski
  • 5
  • 3
9 Comments
 
LVL 23

Expert Comment

by:chensu
Comment Utility
It should work in 16-bit the same as in 32-bit. It is an MFC virtual function. Try CWinApp::PreTranslateMessage() to see if it gets called.
0
 

Author Comment

by:postrowski
Comment Utility
I've tried it at the CWinApp level, and it never got called there either.
0
 
LVL 23

Accepted Solution

by:
chensu earned 100 total points
Comment Utility
Are your sure the prototype of PreTranslateMessage() function is correct?
virtual BOOL PreTranslateMessage(MSG *pMsg);

If so, you have to do some debugging. Open MFC source code appcore.cpp and set some breakpoints in CWinApp::Run() and CWinApp::PumpMessage() to find out why it is not called. I guess the base class function CWinApp::PreTranslateMessage() and CWnd::PreTranslateMessage() are called. But the execution does not go through your overriden version.
0
 

Author Comment

by:postrowski
Comment Utility
I have the prototype correct.
When I set up breakpoints in the App's PreTranslateMessage, I find that I can receive PreTranslateMessage calls up until I launch the new dialog with the DoModal().  At this point, even the App's PreTranslateMessage no longer gets called.
The new dialog is being created by a modless dialog.
The DoModal() call occurs directly after recieving a message to launch the new dialog, thus the App's PreTranslateMessage is already in the call stack when the new dialog is up.  Could this be causing some sort of problem?
Also, I'm not explicitly setting the m_pMainWnd before I call DoModal on the new dialog, could that also be the problem?

Your proposed 'answer' is correct, in that is what I needed to do next, but it still doesn't help me yet.

Do you have any other ideas?

Thanks for your help.
0
Top 6 Sources for Identifying Threat Actor TTPs

Understanding your enemy is essential. These six sources will help you identify the most popular threat actor tactics, techniques, and procedures (TTPs).

 
LVL 23

Expert Comment

by:chensu
Comment Utility
You said "The DoModal() call occurs directly after recieving a message to launch the new dialog, thus the App's PreTranslateMessage is already in the call stack when the new dialog is up." How do you send the message? SendMessage or PostMessage? Use PostMessage instead of SendMessage. And you'd better set m_pMainWnd because some parts of MFC code need it.
0
 

Author Comment

by:postrowski
Comment Utility
What I meant is that the user clicks on a button to launch the new dialog.  In the OnButtonClicked function for that button (which is called through windows messaging), I then call SendMessage to call a routine that launches the dialog with a DoModal call.
Changing this to a PostMessage call has no effect.

I tried to set m_pMainWnd, but quickly learned that it is a member of CWinThread, which doesn't exist in 16-bit.
0
 
LVL 23

Expert Comment

by:chensu
Comment Utility
m_pMainWnd exists in 16-bit, it is a member of CWinApp.
0
 
LVL 23

Expert Comment

by:chensu
Comment Utility
I have tried a simple program which has the same symptom as your program. So, I think there is nothing wrong with your program. That is the restriction of 16-bit MFC. In order to do what you want, you can derive your own edit box class from CEdit and create it in the CDialog::OnInitDialog().
0
 

Expert Comment

by:fredjones
Comment Utility
You don't have to write your own CEdit class.  You can do what you want by added a function to handle the EN_UPDATE message from the edit box.  It will pass you notification before it updates the screen.  You can get the data into your member variable by using the UpdateData(TRUE) function, check and/or modify the value, and then do an UpdateData(FALSE) to put it back on the screen.
0

Featured Post

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

This article shows a few slightly more advanced techniques for Windows 7 gadget programming, including how to save and restore user settings for your gadget and how to populate the "details" panel that is displayed in the Windows 7 gadget gallery.  …
For a while now I'v been searching for a circular progress control, much like the one you get when first starting your Silverlight application. I found a couple that were written in WPF and there were a few written in Silverlight, but all appeared o…
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
In this tutorial you'll learn about bandwidth monitoring with flows and packet sniffing with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're interested in additional methods for monitoring bandwidt…

728 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

11 Experts available now in Live!

Get 1:1 Help Now