CXTCheckListBox Horizontal Scrolling

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   Hi,
I have used CXTCheckListBox in my project and need horizontal scrollbars in the same.
While creating the list box I have specified the WS_HSCROLL property, but that is not enough for CXTCheckListBoxes. By surfing and a little research I came up with the following code which successfully adds a Horizontal scrollbar to my CXTCheckListBox :

    CString cstr;
    CSize   sz;
    int     iMaxLength = 0;
    CDC*    pDC = m_UnroutedTrailsList.GetDC();
    for (int i = 0; i < m_UnroutedTrailsList.GetCount(); i++)
    {
        m_UnroutedTrailsList.GetText(i, cstr);
        sz = pDC->GetTextExtent(cstr);
        if (sz.cx > iMaxLength)
        {
            iMaxLength = sz.cx;
        }
    }
    m_UnroutedTrailsList.ReleaseDC(pDC);
    // Set the horizontal extent so every character of all strings
    // can be scrolled to.
    m_UnroutedTrailsList.SetHorizontalExtent(iMaxLength);

But the problem is that when I scroll the list box horizontally, the strings are not displayed properly. I think there is some refresh problem. The strings are incorrectly drawn (overlap) as I scroll the listbox. The strings get correctly displayed when I click on any item within the CheckListBox.

Can anyone please help me to fix this display problem so that the horizontal scrollbar can behave normally with a CXTCheckListBox?

An early response is eagerly awaited... 

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devam Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 20 March 2008 Location: India Status: Offline Points: 15	Post Options Post Reply Quote devam Report Post Thanks(0) Quote Reply Topic: CXTCheckListBox Horizontal Scrolling Posted: 19 May 2008 at 6:52am
	Hi, I have used CXTCheckListBox in my project and need horizontal scrollbars in the same. While creating the list box I have specified the WS_HSCROLL property, but that is not enough for CXTCheckListBoxes. By surfing and a little research I came up with the following code which successfully adds a Horizontal scrollbar to my CXTCheckListBox : CString cstr; CSize sz; int iMaxLength = 0; CDC* pDC = m_UnroutedTrailsList.GetDC(); for (int i = 0; i < m_UnroutedTrailsList.GetCount(); i++) { m_UnroutedTrailsList.GetText(i, cstr); sz = pDC->GetTextExtent(cstr); if (sz.cx > iMaxLength) { iMaxLength = sz.cx; } } m_UnroutedTrailsList.ReleaseDC(pDC); // Set the horizontal extent so every character of all strings // can be scrolled to. m_UnroutedTrailsList.SetHorizontalExtent(iMaxLength); But the problem is that when I scroll the list box horizontally, the strings are not displayed properly. I think there is some refresh problem. The strings are incorrectly drawn (overlap) as I scroll the listbox. The strings get correctly displayed when I click on any item within the CheckListBox. Can anyone please help me to fix this display problem so that the horizontal scrollbar can behave normally with a CXTCheckListBox? An early response is eagerly awaited...
	DC

mgampi Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 14 July 2003 Status: Offline Points: 1201	Post Options Post Reply Quote mgampi Report Post Thanks(0) Quote Reply Posted: 19 May 2008 at 11:03am
	Hi; what about adding a OnHScroll handler and after calling the base class implementation do a simple window refresh?
	Martin Product: Xtreme Toolkit v 22.1.0, new Projects v 24.0.0 Platform: Windows 10 v 22H2 (64bit) Language: VC++ 2022

devam Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 20 March 2008 Location: India Status: Offline Points: 15	Post Options Post Reply Quote devam Report Post Thanks(0) Quote Reply Posted: 20 May 2008 at 1:22am
	Thanks for the suggestion but I tried that as well. Problem is that I have a dialog on which the CCheckListBox is a control. So, since I do not have a wrapper class over the control, I cannot handle WM_HSCROLL message. If I do, it will get handled for the dialog class and not the control. Is there any way in which I can handle the message while keeping the CheckListBox as a control within a dialog?
	DC

mgampi Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 14 July 2003 Status: Offline Points: 1201	Post Options Post Reply Quote mgampi Report Post Thanks(0) Quote Reply Posted: 20 May 2008 at 3:03am
	Hi; You have to derive from CXTPCheckListBox class and handle WM_HSCROLL there. Then declare a dialog member variable of type of the derived class and in DoDataExchange do a DDX_Control(). HTH
	Martin Product: Xtreme Toolkit v 22.1.0, new Projects v 24.0.0 Platform: Windows 10 v 22H2 (64bit) Language: VC++ 2022

devam Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 20 March 2008 Location: India Status: Offline Points: 15	Post Options Post Reply Quote devam Report Post Thanks(0) Quote Reply Posted: 20 May 2008 at 3:11am
	What you are suggesting is to create a class of my own for the control that I am using. That is the correct approach, but is not feasible for my project currently due to lack of time and resources. I was wondering if there is any workaround through which I could properly handle the horizontal scrollbar while keeping the CXTPCheckListBox as a control within the dialog, and not creating a class for it. Thanks a lot for the suggestion, but a little insight on this workaround, if possible, would be greatly appreciated.
	DC

mgampi Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 14 July 2003 Status: Offline Points: 1201	Post Options Post Reply Quote mgampi Report Post Thanks(0) Quote Reply Posted: 20 May 2008 at 3:13am
	Hi; you dont have to create your own class from scratch. Only derive it to handle WM_HSCROLL. This requires about 15 minutes to be realized...
	Martin Product: Xtreme Toolkit v 22.1.0, new Projects v 24.0.0 Platform: Windows 10 v 22H2 (64bit) Language: VC++ 2022