Radio Buttons in MFC (Visual Studio 2008 / C++)
This is a quick and dirty description of how to use radio buttons in MFC, written because I could not find this information in a single place on the web.
In the dialog editor:
- Create a new group with the group box control and set a meaningful caption
- Add radio button controls inside the group
- The radio buttons must have ascending tab order
- The first radio button (in tab order) must have the property “Group” set to True
- All other radio buttons must have the property “Group” set to False
It should look similar to this:
In the header file defining the dialog class:
- Add a member variable of type int that will store which radio button is selected (none: -1, first: 0, second: 1, and so on).
In the cpp file implementing the dialog class:
- In the constructor initialize the member variable (with 0)
CDialogConfig::CDialogConfig(CMainFrame* pMainFrame) : CDialog(CDialogConfig::IDD, pMainFrame), m_nLEDType(0)
- In DoDataExchange add a call to DDX_Radio similar to the following (where IDC_RADIO_LEDTYPE1 is the ID of the first radio button):
DDX_Radio(pDX, IDC_RADIO_LEDTYPE1, m_nLEDType);
When you want to read which radio button is selected:
- Call UpdateData with a parameter of true (indicates reading):
- After UpdateData has been called, the member variable (m_nLEDType in this example) has the current state of the buttons.
When you want to select one of the buttons programmatically:
- Set the member variable to the correct value (none selected: -1, first button selected: 0, second button selected: 1, and so on)
- Call UpdateData with a parameter of false (indicates writing):