Solved

CScrollBar Messages

Posted on 2000-04-03
7
344 Views
Last Modified: 2013-11-20
I am trying to process a on LBUTTONUP message for a scroll bar. But it doesn't seem to be getting one. I can see from the spy tool that one is being sent, but my scroll bar class is not picking it up. Can anyone tell me where this message is going and how to process it?
0
Comment
Question by:wrobel
7 Comments
 
LVL 4

Expert Comment

by:captainkirk
ID: 2680502
Try deriving your own scroll bar class and overriding PreTranslateMessage() to catch it there.
0
 
LVL 1

Expert Comment

by:mahno
ID: 2680710
Hi wrobel,

U can add to dialog function:
void CTESTDlg::OnVScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)
{
  if (nSBCode == SB_ENDSCROLL) {
    //This message such as WM_LBUTTONUP
    //Add your code here...
  }

  CDialog::OnVScroll(nSBCode, nPos, pScrollBar);
}

Or U can use captainkirk, method

Hope that helps,
  mahno
0
 

Author Comment

by:wrobel
ID: 2683197
I'm sure what you were trying to tell me. I need to find out if the left mouse button is up or not. I did what captainkirk said but the message doesn't even get there. It seem to be lost when my program runs through some RTL2( a really old language) code, which is called in my scroll down code.
0
U.S. Department of Agriculture and Acronis Access

With the new era of mobile computing, smartphones and tablets, wireless communications and cloud services, the USDA sought to take advantage of a mobilized workforce and the blurring lines between personal and corporate computing resources.

 
LVL 31

Accepted Solution

by:
Zoppo earned 100 total points
ID: 2683475
Hi wrobel,

only way I found is via MouseHook, i.e.:


// In .h file
class CMyScroll : public CScrollBar
{
 ...
 static HHOOK sbHook;
 static HWND sbHandle;

 static LRESULT CALLBACK MouseHook(int nCode, WPARAM wParam, LPARAM lParam);
 ...
};

// In .cpp file
HHOOK CMyScroll::sbHook = NULL;
HWND CMyScroll::sbHandle = NULL;

LRESULT CALLBACK CMyScroll::MouseHook(int nCode, WPARAM wParam, LPARAM lParam)
{
 MOUSEHOOKSTRUCT *mh = (MOUSEHOOKSTRUCT *)lParam;
 if ( mh->hwnd == sbHandle && wParam == WM_LBUTTONUP )
 {
  ::PostMessage( sbHandle, WM_LBUTTONUP, MAKELPARAM( mh->pt.x, mh->pt.y ), 0 );
 }
 return  CallNextHookEx( sbHook, nCode, wParam, lParam );
}

void CMyScroll::OnLButtonDown(UINT nFlags, CPoint point)
{
 m_bDown = TRUE;
 sbHandle = m_hWnd;
 sbHook = SetWindowsHookEx( WH_MOUSE, MouseHook, NULL, AfxGetThread()->m_nThreadID );
 CScrollBar::OnLButtonDown(nFlags, point);
}

void CMyScroll::OnLButtonUp(UINT nFlags, CPoint point)
{
 if( NULL != sbHook )
 {
  UnhookWindowsHookEx( sbHook );
  sbHook = NULL;
 }
 AfxMessageBox( "Left Button Up!" );
 CScrollBar::OnLButtonUp(nFlags, point);
}

hope that helps,

ZOPPO
0
 

Author Comment

by:wrobel
ID: 2689089
Adjusted points from 50 to 100
0
 

Author Comment

by:wrobel
ID: 2689090
Excellent that worked a treat, thank you very much for you answer.
0
 
LVL 31

Expert Comment

by:Zoppo
ID: 2689093
I'm glad I could help you,

have a nice day,

ZOPPO
0

Featured Post

3 Use Cases for Connected Systems

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, testing some more, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction: Finishing the grid – keyboard support for arrow keys to manoeuvre, entering the numbers.  The PreTranslateMessage function is to be used to intercept and respond to keyboard events. Continuing from the fourth article about sudoku. …
Have you tried to learn about Unicode, UTF-8, and multibyte text encoding and all the articles are just too "academic" or too technical? This article aims to make the whole topic easy for just about anyone to understand.
This Micro Tutorial will give you a basic overview how to record your screen with Microsoft Expression Encoder. This program is still free and open for the public to download. This will be demonstrated using Microsoft Expression Encoder 4.
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.

778 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question