MFC - Radio Buttons

A radio button is a control that appears as a dot surrounded by a round box. In reality, a radio button is accompanied by one or more other radio buttons that appear and behave as a group.

Here is the list of methods in Radio Button class.

Sr.No.	Name & Description
1	Create Creates the Windows button control and attaches it to the CButton object.
2	DrawItem Override to draw an owner-drawn CButton object.
3	GetBitmap Retrieves the handle of the bitmap previously set with SetBitmap.
4	GetButtonStyle Retrieves information about the button control style
5	GetCursor Retrieves the handle of the cursor image previously set with SetCursor.
6	GetIcon Retrieves the handle of the icon previously set with SetIcon.
7	GetIdealSize Retrieves the ideal size of the button contro.
8	GetImageList Retrieves the image list of the button control.
9	GetNote Retrieves the note component of the current command link control.
10	GetNoteLength Retrieves the length of the note text for the current command link control.
11	GetSplitGlyph Retrieves the glyph associated with the current split button control.
12	GetSplitImageList Retrieves the image list for the current split button control.
13	GetSplitInfo Retrieves information that defines the current split button control.
14	GetSplitSize Retrieves the bounding rectangle of the drop-down component of the current split button control.
15	GetSplitStyle Retrieves the split button styles that define the current split button control.
16	GetState Retrieves the check state, highlight state, and focus state of a button control.
17	GetTextMargin Retrieves the text margin of the button control.
18	SetBitmap Specifies a bitmap to be displayed on the button.
19	SetButtonStyle Changes the style of a button.
20	SetCheck Sets the check state of a button control.
21	SetCursor Specifies a cursor image to be displayed on the button.
22	SetDropDownState Sets the drop-down state of the current split button control.
23	SetIcon Specifies an icon to be displayed on the button.
24	SetImageList Sets the image list of the button control.
25	SetNote Sets the note on the current command link control.
26	SetSplitGlyph Associates a specified glyph with the current split button control.
27	SetSplitImageList Associates an image list with the current split button control.
28	SetSplitInfo Specifies information that defines the current split button control.
29	SetSplitSize Sets the bounding rectangle of the drop-down component of the current split button control.
30	SetSplitStyle Sets the bounding rectangle of the drop-down component of the current split button control.
31	SetState Sets the highlighting state of a button control.
32	SetTextMargin Sets the text margin of the button control.

Here is the list of messages mapping for Radio Button control −

Message	Map entry	Description
BN_CLICKED	ON_BN_CLICKED( <id>, <memberFxn> )	The framework calls this member function when is button clicked.
BN_DISABLE	ON_BN_DISABLE( <id>, <memberFxn> )	The framework calls this member function when button is disabled.
BN_DOUBLECLICKED	ON_BN_DOUBLECLICKED( <id>, <memberFxn> )	The framework calls this member function when button is double clicked.
BN_PAINT	ON_BN_PAINT( <id>, <memberFxn> )	The framework calls this member function when an application makes a request to repaint a button.

Let us look into an example of Radio button by creating a new MFC dialog based application.

Step 1 − Drag a group box and three radio buttons and remove the Caption of Static Text control.

Step 2 − Add event handler for all the three radio buttons.

Step 3 − Add the Value variable for the Static Text control.

Step 4 − Here is the implementation of three event handlers.

void CMFCRadioButtonDlg::OnBnClickedRadio1() {
   // TODO: Add your control notification handler code here
   m_strTextControl = _T("Radio Button 1 Clicked");
   UpdateData(FALSE);
}

void CMFCRadioButtonDlg::OnBnClickedRadio2() {
   // TODO: Add your control notification handler code here
   m_strTextControl = _T("Radio Button 2 Clicked");
   UpdateData(FALSE);
}

void CMFCRadioButtonDlg::OnBnClickedRadio3() {
   // TODO: Add your control notification handler code here
   m_strTextControl = _T("Radio Button 3 Clicked");
   UpdateData(FALSE);
}

Step 5 − When the above code is compiled and executed, you will see the following output. When you select any radio button, the message is displayed on Static Text control.

mfc_windows_controls.htm