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Visual C++ Example: How to swap two items of  CListView, GetItem, GetItemState

In some occasions, you might want to allow the user the change the order of items in the ListView, by moving the selected items up and down. In the API of ListView control, there is no support for swapping between 2 items. The only way to do that, is by manually swapping all data of the items, including the lParam value and all columns !
The following code snippet demonstrate how to do that. The SwapLVItems function swap between 2 items (iItem1 and iItem2 are the index of the items in the ListView).

The MoveLVSelectedItemsUp and MoveLVSelectedItemsDown functions move the selected items up and down.

UINT GetLVItemState(HWND hwnd, int i, UINT mask)

{
        return ListView_GetItemState(hwnd, i, mask);
}
void GetLVItemText(HWND hwnd, int iItem, int iSubItem, LPSTR pszText, int cchTextMax)
{
        ListView_GetItemText(hwnd, iItem, iSubItem, pszText, cchTextMax);
}
void SetLVItemText(HWND hwnd, int i, int iSubItem, LPSTR pszText)
{
        ListView_SetItemText(hwnd, i, iSubItem, pszText);
}
BOOL GetLVItem(HWND hListView, UINT mask, int iItem, int iSubItem, 

               LPLVITEM pitem, UINT stateMask)

{

        pitem->mask = mask;

        pitem->stateMask = stateMask;

        pitem->iItem = iItem;

        pitem->iSubItem = iSubItem;

        return ListView_GetItem(hListView, pitem);

}
int GetHeaderItemCount(HWND hwndHD)

{

        return Header_GetItemCount(hwndHD);

}
HWND GetLVHeaderControl(HWND hListView)

{

        return ListView_GetHeader(hListView);

}
int GetLVColumnsCount(HWND hListView)

{
        return (GetHeaderItemCount(GetLVHeaderControl(hListView)));

}
void SwapLVItems(HWND hListView, int iItem1, int iItem2)

{

        //I assume that 4K buffer is really enough for storing the content of a column

        const LOCAL_BUFFER_SIZE = 4096;

        LVITEM lvi1, lvi2;

        UINT uMask = LVIF_TEXT | LVIF_IMAGE | LVIF_INDENT | LVIF_PARAM  | LVIF_STATE;

        char szBuffer1[LOCAL_BUFFER_SIZE + 1], szBuffer2[LOCAL_BUFFER_SIZE + 1];

        lvi1.pszText = szBuffer1;

        lvi2.pszText = szBuffer2;

        lvi1.cchTextMax  = sizeof(szBuffer1);

        lvi2.cchTextMax  = sizeof(szBuffer2);


 
        BOOL bResult1 = GetLVItem(hListView, uMask, iItem1, 0, &lvi1, (UINT)-1);

        BOOL bResult2 = GetLVItem(hListView, uMask, iItem2, 0, &lvi2, (UINT)-1);


 
        if (bResult1 && bResult2)

        {

               lvi1.iItem = iItem2;

               lvi2.iItem = iItem1;

               lvi1.mask = uMask;

               lvi2.mask = uMask;

               lvi1.stateMask = (UINT)-1;

               lvi2.stateMask = (UINT)-1;

               //swap the items

               ListView_SetItem(hListView, &lvi1);

               ListView_SetItem(hListView, &lvi2);


 
               int iColCount = GetLVColumnsCount(hListView);

               //Loop for swapping each column in the items.

               for (int iIndex = 1; iIndex < iColCount; iIndex++)

               {

                       szBuffer1[0] = '\0';

                       szBuffer2[0] = '\0';

                       GetLVItemText(hListView, iItem1, iIndex, 

                                      szBuffer1, LOCAL_BUFFER_SIZE);

                       GetLVItemText(hListView, iItem2, iIndex, 

                                      szBuffer2, LOCAL_BUFFER_SIZE);

                       SetLVItemText(hListView, iItem2, iIndex, szBuffer1);

                       SetLVItemText(hListView, iItem1, iIndex, szBuffer2);

               }

        }

}
//Move up the selected items

void MoveLVSelectedItemsUp(HWND hListView)

{

        int iCount = ListView_GetItemCount(hListView);


 
        for (int iIndex = 1; iIndex < iCount; iIndex++)

               if (GetLVItemState(hListView, iIndex, LVIS_SELECTED) != 0)

                       SwapLVItems(hListView, iIndex, iIndex - 1);


 
}
//Move down the selected items

void MoveLVSelectedItemsDown(HWND hListView)

{
        int iCount = ListView_GetItemCount(hListView);


 
        for (int iIndex = iCount - 1; iIndex >= 0; iIndex--)

               if (GetLVItemState(hListView, iIndex, LVIS_SELECTED) != 0)

                       SwapLVItems(hListView, iIndex, iIndex + 1);


 
}

Visual C++ 6.0, Visual C++.net 2003, VC++ .NET 2005, MFC Source Code

 

 

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