Win32 ListView control doesn't display any icons

Jonathan Davies

Using VS2008 Prof. on Windows8, a Win32 ListView control in Report mode doesn't display any icons at the start of each row. It shows data which I can sort, but no icons. I'm assuming its some bit or attribute not set somewhere so have to show all the relevant code for someone to see what I'm missing. The list (header)setup code is here (followed by the row insertion code taken out of its loop and then my test code). All error handling removed. I've compared this to an ATL/WTL program that shows the icons and I can't see any difference. The image list is initialised by the CDeviceImageList constructor which uses the below code to initialize the list:

class CDeviceImageList
{
private:
SP_CLASSIMAGELIST_DATA m_spImageData; //!< Structure containing class image list information.
public:
/**
Builds an image-list that contains bitmaps for every installed device-class.
*/
CDeviceImageList()
{
RtlZeroMemory(&m_spImageData, sizeof(SP_CLASSIMAGELIST_DATA));
m_spImageData.cbSize = sizeof(SP_CLASSIMAGELIST_DATA);
BOOL b = SetupDiGetClassImageList(&m_spImageData);
if(FALSE == b)
{
assert(!"Failed to aquire class image list");
}
}

operator HIMAGELIST() const throw()
{ 
	return m\_spImageData.ImageList; 
}

...

ListView setup before the data ...

LVITEM lvItem;
SecureZeroMemory(&lvItem, sizeof(LVITEM));

LVCOLUMN lvCol;
SecureZeroMemory(&lvCol, sizeof(LVCOLUMN));

HWND hList=GetDlgItem(hwnd,IDC\_LIST1);

lvCol.pszText=L"Port";                                  // First Header Text
lvCol.mask=LVCF\_TEXT;                                   // .pszText is valid

  
lvCol.cx=60;                                            // width of coloumn 1
lvCol.mask   |= LVCF\_WIDTH;                             // .cx (width) is valid
  

lvCol.iSubItem = 0;                                     // Col 0
lvCol.mask  |= LVCF\_SUBITEM;                            // .iSubItem is valid                         

lvCol.fmt   = HDF\_SORTUP;                               // Set an up arrow 
lvCol.fmt     |= LVCFMT\_LEFT;                           // and left-align the column.
lvCol.mask  |= LVCF\_FMT;                                // .format is valid

int nCol = 0;
nCol = ListView\_InsertColumn(hList, lvCol.iSubItem, &lvCol);



lvCol.iSubItem = 1;                                     // Col 1
lvCol.pszText=L"Device";

Lost User

Hi, How are you creating your image list? Are these 32 bit icons? About Image Lists[^] Best Wishes, -David Delaune

Lost User

CDeviceImageList cImageList;
HIMAGELIST hImageList = cImageList;

HIMAGELIST hRet = ListView\_SetImageList(hList,  hImageList, LVSIL\_SMALL,);

I note that you are using the CDeviceImageList class from this Article[^], in which case you should post your question in the forum at the end of the article to dicuss with the author. Although it looks to me that you have not initialised the object with any icons.

Use the best guess

Jonathan Davies

Richard, I've asked the Author of that CDeviceImageList class article you refer to (me) and he's sure the list is initialized - though he cold of course be wrong. I've now added the code from the constructor of this class to the question to show how its initialized. Tp prove the ListView ImageList is initialized, After setting up the list I can use the three lines show at the end of my question, which are basically,

GetDialog, GetListView, GetIcon

, followed by

SendMessage(hwnd, WM_SETICON, ICON_SMALL, (LPARAM)hIcon);

to display the exactly the icon I'm looking for in the top-left corner of the dialog box. Which seems to prove the initialization.

Jonathan Davies

David, I've now added the code showing the creation of the image list to my question as you're not the only one to ask how it's created or initialized. Basically my CDeviceImageList constructor uses a call to SetupDiGetClassImageList[^]. At the end of my list setup and data initialization I can use the last three lines of code shown to basically: GetDialog, GetListView, and GetIcon followed by a call to

SendMessage(hwnd, WM_SETICON, ICON_SMALL, (LPARAM)hIcon);

to display in the top-left corner of the dialog the very icon I expect to see in the ListView. which would seem to prove the ImageList in the ListView has the icons. Are they 32 bit? Not to my knowledge. I've read the stuff on ImageLists, ListViews etc. until I almost know it by heart.

Lost User

Then that suggests that you are not usiing the correct values when you add an item to the ListView. I would suggest you step through with your debugger to see which icon index is being used when you add an item to the control.

Use the best guess

Jonathan Davies

Richard, Stepped through it repeatedly, also side by side comparing it with working ATL/WTL example. I've just typed and run the below test at the end of the loop that fills rows with data where n is the loop variable. I get the LVITEM.iImage which is the index for the row, get a completely new ImageList from the ListView and get the icon from that ImageList successfully and can display it in the dialog top-left corner for any n.

LVITEM lvItemP2;
SecureZeroMemory(&lvItemP2, sizeof(LVITEM));
lvItemP2.mask = LVIF\_IMAGE;
lvItemP2.iItem = n;
BOOL bGotItem2 = ListView\_GetItem(hList,  &lvItemP2);

HIMAGELIST hNewImageList =  ListView\_GetImageList(hList, LVSIL\_SMALL);
if(NULL == hNewImageList)
{
    DWORD dwErr = GetLastError(); 
    std::wstring szErr = CWin32ErrToWString()(dwErr);
    assert(!"Failed to get image list during test");
}

HICON hIconP2 = ImageList\_GetIcon(hNewImageList, lvItemP2.iImage, ILD\_NORMAL);
if(NULL == hIconP2)
{
    DWORD dwErr = GetLastError(); 
    std::wstring szErr = CWin32ErrToWString()(dwErr);
    assert(!"Failed to get icon from image list during test");
}
SendMessage(hwnd, WM\_SETICON, ICON\_SMALL, (LPARAM)hIconP2);

Lost User

All well and good, but it does not really address your problem, which is about setting the imagelist and image index correctly in your list view items.

Use the best guess

Jonathan Davies

I'd say that getting the imagelist from the listview and getting the index into that list from each set of row data and using that index into the imagelist to come up with the expected icon shows I'm setting the imagelist and index correctly and the reason for non-display must be something else. Stepping through each row item is set with image-index 0x1A, and this is also the value extracted from each row item after setting it. The imagelist when obtained is of size 0x4A images as is the imagelist extracted from the listview later.

Lost User

You are quite right, I mis-read what was happening there. I am afraid I cannot think of anything else to suggest. I have been looking at my own sample ListView program and it works fine, although I do creae the imagelist myself.

Use the best guess

Lost User

I just ran a very quick test and got it to work; we need to compare code more closely. But that's a job for tomorrow, there's a bottle of Shiraz in the dining room that's calling my name.

Use the best guess

Jonathan Davies

Richard, Created an ImageList of the same size from an icon resource and it worked. Same size etc. Then it hit me, in the WTL project I took this from my CDeviceImageList object was a class variable and in my win32 project I'd declared it in the InitDialog function. In its constructor CDeviceImageList calls: SetupDiGetClassImageList but in its destructor it calls SetupDiDestroyClassImageList As it went out of scope ... Anyway thanks for the help

Lost User

I have made similar mistakes more times than I care to recall. Glad you got it sorted.

Use the best guess