Accessing MFC Dialog Box Controls

I have a dialog box in MFC that has a few controls on it (lables, textboxes, etc.) and I can't figure out how to access them in the code. I just want to read and write to common properties like Caption, etc., but I just can't find out how.

Open up MFC ClassWizard
Select "Member VariableS" tab
Select the "Control ID" for the desired control (text box, etc.)
Select Add Variable
Give it a name and type

For example for edit box with ID "IDC_DATE_DAY" a variable is created for it called m_date_day of type float.

The varible declaration is automatically put in the dialog class definition in the header file.

For example:

class CDateDlg : public CDialog
{
public:
CDateDlg(CWnd* pParent = NULL); // standard constructor
enum { IDD = IDD_DATE_DIALOG };
...
float m_date_day;
...
};

Thes variable is initialized in dialog class constructor.

CDateDlg::CDateDlg(CWnd* pParent /*=NULL*/)
: CDialog(CDateDlg::IDD, pParent)
{
//{{AFX_DATA_INIT(CDateDlg)
m_date_day = 0.0f;
//}}AFX_DATA_INIT
}

If you enter something in the edit box and want to get the value You must use this statement before doing so: UpdateData(TRUE);

For example suppose you want to read the value from the "IDC_DATE_DAY" edit box after it is entered into a variable called newday:

float newday;
UpdateData(TRUE);
newday = m_date_day;

To reverse the process you need to use this statement to force the edit box to receive a new value: UpdateData(FALSE);

For example suppose you want to write the value to the "IDC_DATE_DAY" edit box from a variable called newday:

float newday;
newday = 20.75;
m_date_day = newday;
UpdateData(FALSE);

Thanks