Microsoft KB Archive/102828

{|
 * width="100%"|

Listbox Using Microsoft Foundation Classes

 * }

Q102828

-

The information in this article applies to:


 * The Microsoft Foundation Classes (MFC), used with:
 * Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5, 1.51, 1.52
 * Microsoft Visual C++, versions 1.0, 2.0, 2.1

-

This is the 16-bit version of this sample. There is an equivalent 32-bit sample available under the name Lstddx32.EXE.

For additional information on how to obtain Lstddx32.exe, click the article number below to view the article in the Microsoft Knowledge Base:

"Q141498 INFO: Filling List Box Using MFC's DDX Facility"

SUMMARY
The LSTDDX sample illustrates a technique for filling both an ordinary listbox control and the listbox portion of a combo control with data, and using the Microsoft Foundation Class (MFC) Dialog Data Exchange (DDX) facility to return the selection.

MORE INFORMATION
The following files are available for download from the Microsoft Download Center:

"Lstddx.exe" For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base:

"Q119591 How to Obtain Microsoft Support Files from Online Services" Microsoft used the most current virus detection software available on the date of posting to scan this file for viruses. Once posted, the file is housed on secure servers that prevent any unauthorized changes to the file.

NOTE: Use the -d option when running LSTDDX.EXE to decompress the file and re-create the proper directory structure.

A common misconception with regard to DDX is that assigning a value to a DDX variable will cause that data to be loaded into a control. This does in fact happen for edit controls, but not for listbox controls. In order to add items to a listbox the dialog class must use the CListBox::AddString or CComboBox::AddString functions. Doing this involves several steps which are illustrated by this sample.

The sample itself was initially created as an MDI application using AppWizard from Visual C++ version 1.0. AppStudio was then used to create a dialog which contains OK and Cancel button plus an edit control (IDC_EDIT1), a combo control (IDC_COMBO1), and a listbox control (IDC_LIST1). The Class Wizard was used to create a class CDialog1 based on CDialog. The files dialog1.h and dialog1.cpp contain the code for this class. Class Wizard was also used to add DDX member variables m_edit1, m_combo1, and m_list1 to dialog1.h. A menu item was added to the view menu (IDR_LIST_DTYPE) using AppStudio, and a message handler added which will call the dialog when the menu item was selected.

The README.TXT file included with the sample explains in more detail how the listboxes are initialized and how data is passed between the calling routine and the dialog procedure.