Microsoft KB Archive/143410

= DOC: Vertical Slider Control Sends WM_VSCROLL Message =

Article ID: 143410

Article Last Modified on 11/21/2006

-

APPLIES TO

 Microsoft Foundation Class Library 4.2, when used with:  Microsoft Visual C++ 4.0 Standard Edition

 Microsoft Visual C++ 4.1 Subscription

 Microsoft Visual C++ 4.2 Enterprise Edition

 Microsoft Visual C++ 4.2 Professional Edition</li></ul>

 Microsoft Visual C++ 5.0 Enterprise Edition</li></ul>

 Microsoft Visual C++ 5.0 Professional Edition</li></ul> </li></ul>

-

<div class="notice_section">

This article was previously published under Q143410

<div class="summary_section">

SUMMARY
The following paragraph from MFC Technical Note 60 is incomplete.

"Slider Notification Messages

A slider control notifies its parent window of user actions by sending the parent WM_HSCROLL messages. You can override the parent's OnHScroll member function to handle these messages. This function will be passed a notification code, the position of the slider, and a pointer to the CSliderCtrl object. Note that the pointer is of type CScrollBar* even though it points to a CSliderCtrl object. You may need to typecast this pointer if you need to manipulate the slider control."

This information is true only for a HORIZONTAL slider control (a trackbar with the TBS_HORZ style). For a VERTICAL slider control (a trackbar with the TBS_VERT style), the WM_VSCROLL will be sent instead of the WM_HSCROLL message. You should override the parent's OnVScroll member function to handle these messages.

In Visual C++, versions 5.0 and later, the above text is part of the help topic titled "Slider Control Notification Messages."

<div class="moreinformation_section">

MORE INFORMATION
The correct documentation can be found from the Trackbar Notification Messages in Win32 SDK of Visual C++ 4.x Books Online.

A vertical slider control is used in the FIRE sample program. However, in the sample OnHScroll was overridden instead of OnVScroll. Therefore, the code in OnHScroll (intended for the vertical slider control) will not be executed when running this sample. Microsoft has confirmed this to be a bug in the sample in Visual C++ 4.0. To fix this problem with FIRE, replace the OnHScroll handler with an OnVScroll handler. This problem was corrected in Visual C++ 4.1.

Additional query words: CsliderCtrl Trackbar FIRE

Keywords: kbbug kbcmnctrls kbdocerr kbdocfix kbfix kbscrollbar kbuidesign kbvc410fix KB143410

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.