How to implement horizontal scrolling in a CListBox-derived class

The HLISTBOX sample contained in HLISTBOX.EXE illustrates how to implement horizontal scrolling in a CListBox-derived class.

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

Visual C++ 6.0

Download the Hlistbox.exe package now. (http://download.microsoft.com/download/vc40pro/sample2/1/nt4/en-us/hlistbox.exe) For more information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

Visual C++ .NET

Download the Hlistboxvcnet.exe package now. (http://download.microsoft.com/download/visualstudionet/other/1.32/win98mexp/en-us/hlistboxvcnet.exe) Release Date: August 14, 2002

For more information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file. NOTE: Use the -d option when running HLISTBOX.EXE to decompress the file and recreate the proper directory structure.

HLISTBOX implements a new class called CHorzListBox that is derived from CListBox. This new class automatically updates the horizontal extent of a list box to that of the longest string included in the list box. It works well with list boxes that have or don't have the LBS_USETABSTOPS style. An ordinary Windows list box does not attempt to implement horizontal scrolling of this nature.

Basically, the CHorzListBox intercepts all messages that would affect the horizontal extent based on the string lengths. It tracks the extent of all strings in the list box through an array. Examine the source code for details. NOTE: The "Lock/Unlock" button on the main dialog locks and unlocks the automatic updating of horizontal extent for the list box.