Question

MFC Radio button handler called multiple times.

Asked by: arun123prasad

I am using 2 radio buttons.   BUTTON1-Group property set.
I have ON_BN_CLICKED handlers say BUTTON1_Handler(), BUTTON2_Handler().

After clcking on any of the two radio buttons, I display a message box with MB_YESNO style and get confirmation from the user. If user chooses "NO", I have to revert the selection.

If I try to change the state of BUTTON1 using "SetCheck()" inside BUTTON1_Handler(), then BUTTON1_handler() is called multiple times and the messge box is popped up again and again.

Please help me how to change the radio button state inside its own handler...

BUTTON1_Handler()
{
       if( IDNO == AfxMessageBox("Confirm ?",MB_YESNO) )
       {
           m_Button1.SetCheck(0);
           m_Button2.SetCheck(1);
       }
}
 
BUTTON2_Handler()
{
       if( IDNO == AfxMessageBox("Confirm ?",MB_YESNO) )
       {
             m_Button1.SetCheck(1);
             m_Button2.SetCheck(0);
        }
}

                                  
1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:

Select allOpen in new window

This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.

Subscribe now for full access to Experts Exchange and get

Instant Access to this Solution

  • Plus...
  • 30 Day FREE access, no risk, no obligation
  • Collaborate with the world's top tech experts
  • Unlimited access to our exclusive solution database
  • Never be left without tech help again

Subscribe Now

Asked On
2009-04-25 at 02:18:33ID24354695
Tags

VC++

,

MFC

Topic

Windows MFC Programming

Participating Experts
2
Points
250
Comments
3

Trusted by hundreds of thousands everyday for fast, accurate and reliable tech support.

  • "The time we save is the biggest benefit of Experts Exchange to Warner Bros. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange." Mike Kapnisakis, Warner Bros.
  • "Our team likes having a resource that is more secure than just using Google and most experts using this service really know their stuff. It's nice to look here first versus using Google." Dayna Sellner, Lockheed Martin
  • "Anytime that I've been stumped with a problem, 9 out of 10 times Experts Exchange has either the accepted solution or an open discussion of the potential solution to the problem." Kenny Red, eBay Inc.

See what Experts Exchange can do for you.

Got a question?

We've got the answer.

Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.

Screenshot of Experts Exchange Knowledgebase

Need individual assistance?

Our experts are ready to help.

If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.

Screenshot of Experts Exchange Knowledgebase

Want to learn from the best?

Read articles from industry experts.

Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.

Screenshot of an Article

Working on a long term project?

Store your work and research.

Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.

Screenshot of Experts Exchange Knowledgebase

Access the answers to your technology questions today.

Subscribe Now

30-day free trial. Register in 60 seconds.

What Makes Experts Exchange Unique?

Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Trusted by the world's most respected brands.

image of each brand's logo

Faithfully serving IT professionals since 1996.

Experts Exchange Logo

Try it out and discover for yourself.

Subscribe Now

30-day free trial. Register in 60 seconds.

Related Solutions

  1. How to Run program from BN_Clicked
    Under BN_CLICKED what code line do I need to put in to run a applicaton from the hard drive?
  2. CmdUI->SetCheck
    I want a menu item check mark to be toggled when the user clicks on it. This works: void CDlgMain::OnUpdateOptionsRotate(CCmdUI* pCmdUI) { CMenu *Menu = this->GetMenu(); if (Menu != NULL) Menu->CheckMenuItem(ID_OPTIONS_ROTATE, (m_Dx8.bRotation == true)...
  3. ON_BN_CLICKED pointing to the same function
    Hello! I have two buttons IDC_BUT1 and IDC_BUT2. On BN_CLICKED, both buttons point to the same function OnButtonClick. From the function OnButtonClick, how will I know which button triggered the event? I try to do it by using Message Maps but once in the OnButtonClick func...
  4. handle BN_CLICKED message
    hello, all i have derived a subclass "CUserStatic" from CStatic, and want to handle the message BN_CLICKED in this subclass itself, anybody know how to override this message handle?
  5. Message handler parameters for dynamically created MFC …
    I have an MFC application where I dynamically create buttons on a dialog. The buttons derive from CButton and each store a variable integer which is allocated when they are created. At the minute I have written one common message handler for BN_CLICKED and each instance of t...
  6. BN_CLICKED and the message queue
    I'm trying to perfom an operation if a certain button is clicked within a Dialog created with the CDialog constructor and Create. After creating the dialog, I'm going into a loop which processes messages using PeekMessage. The problem is, the WM_COMMAND and BN_CLICKED message...

Free Tech Articles

  1. WARNING: 5 Reasons why you should NEVER fix a computer for free.
    It is in our nature to love the puzzle. We are obsessed. The lot of us. We love puzzles. We love the challenge. We thrive on finding the answer. We hate disarray. It bothers us deep in our soul. W...
  2. SCCM OSD Basic troubleshooting
    SCCM 2007 OSD is a fantastic way to deploy operating systems, however, like most things SCCM issues can sometimes be difficult to resolve due to the sheer volume of logs to sift through and the dispe...
  3. Migrate Small Business Server 2003 to Exchange 2010 and Windows 2008 R2
    This guide is intended to provide step by step instructions on how to migrate from Small Business Server 2003 to Windows 2008 R2 with Exchange 2010. For this migration to work you will need the fo...
  4. Create a Win7 Gadget
    This article shows you how to create a simple "Gadget" -- a sort of mini-application supported by Windows 7 and Vista. Gadgets can be dropped anywhere on the desktop to provide instant information, ...
  5. Outlook continually prompting for username and password
    There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover t...
  6. Backup Exchange 2010 Information Store using Windows Backup
    There seems to be quite a lot of confusion around the ability to backup Exchange 2010 using the built in Windows Backup feature. This stems from the omission of this feature prior to Exchange 2007 s...

Cloud Class Webinars

  1. Avoiding Bugs in Microsoft Access
    Alison Balter takes and in-depth look at avoiding bugs in Access. In this webinar you will learn about using the immediate window to debug your applications, invoking the debugger, using breakpoints to troubleshoot, stepping through code, setting the next statement to execute, ...
  2. Top 10 Best New Features in Visio 2010
    Scott Helmers gives live demonstrations of the top 10 new features in Visio 2010. This webinar will teach you how to create compelling diagrams by adding shapes to the page with a single click, linking the shapes in a diagram to data in Excel (or SQL Server, or SharePoint), ...
  3. IT Consultant Business Secrets Revealed
    Michael Munger, Experts Exchange tech pro and IT consultant, pulls back the curtain on his very successful businesses and answers question on every IT consultant and business owner should know about. He shares secrets on what he did to solve the 5 most common problems in IT, ...
  4. Disaster Recovery and Business Continuity
    Quest CTO, Mike Billon, gives an overview of the steps involved in building a dunamic disaster recovery plan. Through case studies and an examination of software/hardware tooles for monitoring and testing, you'll gain a better understandin of where you are, where you want ...
  5. Organize Your Visio Diagrams with Containers and Lists
    Scott Helmers uses cross functional flowcharts, wireframe diagrams, data graphic legends and seating charts to teach you: how to ustilize all three new structured diagram components in Visio 2010, the best practices for organizeing shapes in previous version of Visio, how to organize ...
  6. How to Us Objects, Properties, Events and Methods in Microsoft Access
    Alison Dalter gives an in-depbth look at objects, properties, events and methods in Microsoft Access. In this webinar you will learn about using the object browser, referring to objects, working with properties and methods, working with object variables, understanding the ...

Join the Community

Give a Little. Get a Lot.

Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.

Join the Community

Answers

 

by: DanRollinsPosted on 2009-04-25 at 17:35:26ID: 24234080

Here is the MFC way to handle a group of radio buttons automatically -- you should never have to do SetCheck()

In the dialog editor, make sure the tab-order of the radio buttons are sequential.
Then in only the first radio button, set the Group checkbox in its properties.
Then right-click that first button and press Ctrl+W (class wizard)
In the Variables page, only the first radio button is listed. Give it a variable name, say,
   m_nRadioGrpSel
This will add a DDX_Radio(...) to the DoDataExchange for the dlg.

Now before you open the dialog, set the member variable to indicate which radio button is set (0...n-1). For instance:

CMyDialog dlg;
dlg.m_nRadioGrpSel= 0; // pre-select the first Rb
if ( IDOK == dlg.DoModal() ) {
   if ( dlg.m_nRadioGrpSel==2 ) {
       // the third Rb was selected
   }
}

If you set...
dlg.m_nRadioGrpSel= -1; // or other invalid value

then none of the radio buttons will be selected when the user first sees the dialog box. Furthermore, the user will not be able to use the Tab key to get to any of the radio buttons in the group (so he can't accidentally select one except by using the mouse).

So we have a way to determine not just the status of individual buttons but the group as a whole, and we can set the desired option on screen by just putting a number (0,1,2...) into a member variable and then using
UpdateData(FALSE)

And conversely, we can set the variable to match the current selection by using:
UpdateData( TRUE )

I think the comments in the attached code should cover it. 

void CD55Dlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CD55Dlg)
	DDX_Radio(pDX, IDC_RADIO1, m_nRadioGrpSel);  // <<--- Note
	//}}AFX_DATA_MAP
}
 
 
BEGIN_MESSAGE_MAP(CD55Dlg, CDialog)
...
	ON_BN_CLICKED(IDC_RADIO1, OnRadioGrpClick) // << note: same fn
	ON_BN_CLICKED(IDC_RADIO2, OnRadioGrpClick)
	ON_BN_CLICKED(IDC_RADIO3, OnRadioGrpClick)
...
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()
 
void CD55Dlg::OnRadioGrpClick() 
{
	int nCurOption= m_nRadioGrpSel;
	UpdateData(TRUE);  // collect the (possibly new) value
 
	if ( nCurOption != m_nRadioGrpSel ) { // user requested to change the settings
	int nResp= AfxMessageBox("Confirm ?",MB_YESNO);
		 if ( nResp == IDNO ) {
			m_nRadioGrpSel= nCurOption;  // revert to earlier value
			UpdateData( FALSE );         
		 }
	}
}
                                              
1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:

Select allOpen in new window

 

by: AndyAinscowPosted on 2009-04-26 at 03:06:45ID: 24235427

You need a boolean flag to prevent the messagebox when you set the radio programatically.
eg (pseudo code).

bool m_bDisplay = false;

Handler1()
{
 if (m_bDisplay)
   return;
m_bDisplay = true;
DisplayWarning;
SetCheck;
m_bDisplay = false;
}

and the same for handler2

 

by: DanRollinsPosted on 2009-04-28 at 14:19:31ID: 24255264

Next time, I shall strive to work harder and provide more information, in hopes that I can earn an A.

20120131-EE-VQP-002

3 Ways to Join

30-Day Free Trial

The Experts

98% positive feedback on 31,087 answers since March 2000. angeliii is a Microsoft Most Valuable Professional for his work with MS SQL Server & Develoment.

He has also proven his knowledge of Visual Basic Programming, PHP Scripting and Oracle Databases.

The Experts

97% positive feedback on 10,752 answers since July 2000. lrmoore has more than 18 years experience in the networking industry.

The six-time Mircosoft MVPs specialties include firewalls, virtual private networking, and network management.

Testimonials

"...and excellent source for support... Kind of like having your very own IT dept." Electriciansnet

Testimonials

"I was apprehensive at signing up at first. However... it has already made my life as an IT administrator much easier." JaCrews

Testimonials

"WOW! You guys have great, active, and knowledgeable people on here." moore50

Business Clients

Business Clients

In the Press

"If you’ve got a question... Experts Exchange can supply an answer.”

In the Press

"...an invaluable aid for both IT professionals and those who require tech support."

In the Press

"where IT professionals provide quick answers on just about any topic"

Business Account Plans

Loading Advertisement...