Visual C++ and MFC Programming 2nd Edition

Chapter 15: Fundamental Controls Visual C++ and MFC Fundamentals

Imagine a control with its identifier has already been added to a dialog box but you want

to change that identifier, for any reason you judge necessary. To do this, you would call

the CWnd::SetDlgCtrlID() method. Its syntax is:

int SetDlgCtrlID(int nID);

This method assigns or changes the identifier of the control that called it. Imagine the

control variable of a control is named m_Edition, you can assign a new identifier to it as

follows:

BOOL CDlgControls::OnInitDialog()

{

CDialog::OnInitDialog();

// TODO: Add extra initialization here

m_Edition.SetDlgCtrlID(0x1882);

return TRUE; // return TRUE unless you set the focus to a control

// EXCEPTION: OCX Property Pages should return FALSE

}

If a control has been created and you need its identifier, you can find it out by calling the

CWnd::GetDlgCtrlID() method. Its syntax is:

int GetDlgCtrlID() const;

This method simply returns the identifier of the control that called it. The value is

returned as an integer. You will mostly use this method to find out if the identifier of a

control matches the one the user has just accessed.

Practical Learning: Using Controls Identifiers

1. Start a new MFC Application named Identification and create it as Dialog Based
   without an About Box


2. Delete the TODO line, the OK and the Cancel buttons


3. From the Controls toolbox, add four Custom Controls and draw them
   horizontally on the dialog box as follows:


4. Set the Class name of the top three custom controls to ScrollBar