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Listview sorting...Can't make it work!

This is a discussion on Listview sorting...Can't make it work! within the Windows Programming forums, part of the Platform Specific Boards category; I've tried several approaches, but none of them seem to work... Here's my latest code for this.. Someone please help! ...

  1. #1
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    Feb 2002
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    Angry Listview sorting...Can't make it work!

    I've tried several approaches, but none of them seem to work...
    Here's my latest code for this.. Someone please help!

    From my windowproc's WM_NOTIFY:
    Code:
    		case LVN_COLUMNCLICK:			
    			// Keep track of sort order and column used for sorting.
    			static int nSortColumn = -1;
    			static BOOL bSortAscending = TRUE;
    			LVITEM lvi;
    
    			// Reverse sort order if column was just previously clicked.
    			if(((NM_LISTVIEW*)lParam)->iSubItem == nSortColumn)
    				bSortAscending = !bSortAscending;
    			else{
    				bSortAscending = TRUE; 
    				nSortColumn = ((NM_LISTVIEW*)lParam)->iSubItem;
    			}
    			// Set item data for each row to column value,
    			// since sort routine gets passed item data only.
    			for(int item=0; item<ListView_GetItemCount(GetDlgItem(hwThis, LIST1)); item++){
    				ListView_GetItem(GetDlgItem(hwThis, LIST1), &lvi);
    				int value = GetLstItemLong(GetDlgItem(hwThis, LIST1), item, ((NM_LISTVIEW*)lParam)->iSubItem);  // numeric sort
    				if(!bSortAscending) { value = -value; }
    				lvi.lParam = (long)&value;
    				ListView_SetItem(GetDlgItem(hwThis, LIST1), &lvi);
    			}
    			LPARAM lParamSort = 0;
    			ListView_SortItems(GetDlgItem(hwThis, LIST1), CompareFunc, lParamSort);
    			break;
    My integer sort function. Both lParam1 & 2 are 0 when i click a columnheader...What's happening here??
    Code:
    int CALLBACK CompareFunc(LPARAM lParam1, LPARAM lParam2, LPARAM lParamSort){
      // First two parameters are item data to be compared.
      // Third parameter is passed from SortItems, not used here.
      if (lParam1 < lParam2) {return -1;}
      if (lParam1 > lParam2) {return  1;}
      return  0;
    }

  2. #2
    Registered User lobo's Avatar
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    Oct 2001
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    if that is exact code you are using, then problem might be that you are not setting

    lvi.mask = LVIF_PARAM;

    prior using lvi structure to set param...
    Ducky likes this.

  3. #3
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    Thanks Lobo!
    That solved the problem, except for that subitems don't display anymore...
    I'll just have to keep trying...

  4. #4
    Registered User lobo's Avatar
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    from msdn (on list views):

    Note that sorting items does not reorder the corresponding subitems. Thus, if any subitems are not callback items, you must regenerate the subitems after you sort them.

  5. #5
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    Feb 2002
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    Aaaargh!!
    Maybe i should start using the online version of MSDN..!

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