C / C++ / MFC

Re: Win32 ListView control doesn't display any icons

16-Jul-13 23:49

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

C++

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.

Richard MacCutchan16-Jul-13 20:59

Re: Win32 ListView control doesn't display any icons

16-Jul-13 20:59

C++

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 Davies16-Jul-13 23:24

Re: Win32 ListView control doesn't display any icons

16-Jul-13 23:24

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

C++

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.

Richard MacCutchan17-Jul-13 1:33

Re: Win32 ListView control doesn't display any icons

17-Jul-13 1:33

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 Davies17-Jul-13 2:27

Re: Win32 ListView control doesn't display any icons

17-Jul-13 2:27

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.

C++

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);

Richard MacCutchan17-Jul-13 4:49

Re: Win32 ListView control doesn't display any icons

17-Jul-13 4:49

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 Davies17-Jul-13 6:42

Re: Win32 ListView control doesn't display any icons

17-Jul-13 6:42

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.

Richard MacCutchan17-Jul-13 7:33

Re: Win32 ListView control doesn't display any icons

17-Jul-13 7:33

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

Jonathan Davies18-Jul-13 0:19

Re: Win32 ListView control doesn't display any icons

18-Jul-13 0:19

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

Richard MacCutchan18-Jul-13 0:39

Re: Win32 ListView control doesn't display any icons

18-Jul-13 0:39

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

Use the best guess

Richard MacCutchan17-Jul-13 7:50

How can make smooth horizontal scroll on ListControl??

17-Jul-13 7:50

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

Sun-Mi Kang14-Jul-13 21:21

Sun-Mi Kang

14-Jul-13 21:21

Hi??
I made 168 columns on my list..

But horizontal scroll is so rough!

I used on CQuickList API... Scroll is working slowly..
CQuickList API is below..
Could you give tips for me how to fix horizontal scroll problem??

[^]

Re: How can make smooth horizontal scroll on ListControl??

Richard MacCutchan14-Jul-13 22:24

How to use listview_insertgroup with custom draw?

14-Jul-13 22:24

Please post your question in the forum at the end of the article.

Use the best guess

JoneLe8614-Jul-13 18:39

JoneLe86

14-Jul-13 18:39

I have a listview with custom draw (virtual list)option and i know how to output the items using drawtext() function, but what about the groups? I have googled but Int find anything, all the examples are MFC or without custom draw?! I just want a native example or method about that

thanks

edit.. you got to be kidding with me?!
I found a comment in says it impossible LOL

http://windows-tech.info/14/45a29ec939d2ff8f.php[^]

is that true?

Re: How to use listview_insertgroup with custom draw?

Richard MacCutchan14-Jul-13 21:19

Re: How to use listview_insertgroup with custom draw?

14-Jul-13 21:19

Have you actually tried implementing groups? As far as I can figure, it makes no difference whether this is 'standard' or owner drawn as the messages and notifications are the same. When and if I get some time I may try it myself.

Use the best guess

JoneLe8619-Jul-13 8:42

JoneLe86

19-Jul-13 8:42

thanks Richard MacCutchan for your replay,,, it seems that there are some ways Undocumented List View Features[^]
which are not documented

beginner question... recursive function

Member 1008957914-Jul-13 5:40

Member 10089579

14-Jul-13 5:40

i have this code and it works fine.

int fatt(int n)
{
    int fattoriale = 1;

    if(n==0)
        return fattoriale;
    else
        return fattoriale=n*fatt(n-1);
}

void main(void)
{
    printf("%d\n",fatt(10));

    fflush(stdin);
    getchar();
}

my question is why it works fine also here ?

int fatt(int n)
{
    int fattoriale = 1;

    if(n==0)
        return fattoriale;
    else
        fattoriale=n*fatt(n-1);
}

void main(void)
{
    printf("%d\n",fatt(10));

    fflush(stdin);
    getchar();
}

in this, there aren't the return in the else.... i am using VS2010 and compile in .c .

thanks

ps: sorry for my english

Santhosh G_14-Jul-13 7:46

Santhosh G_

14-Jul-13 7:46

In release mode it will create compilation error. It creates compilation error in VS2008. I got compilation error "error C4716: 'fatt' : must return a value".

But in debug mode it works as follows.
In both case contents of EAX register is used as the output of fatt() function. In both case EAX holds the output value, therefore the two versions works correctly in debug mode.

The result of imul is available in eax register and that is the expected result from the fatt function.

Following are the disassembly of two versions of fatt() function. First one with return value and next is without return value.

        return fattoriale=n*fatt(n-1);
01182ED2  mov         eax,dword ptr [n] 
01182ED5  sub         eax,1 
01182ED8  push        eax  
01182ED9  call        fatt (1181889h) 
01182EDE  add         esp,4 
01182EE1  imul        eax,dword ptr [n] 
01182EE5  mov         dword ptr [fattoriale],eax 
01182EE8  mov         eax,dword ptr [fattoriale]

        fattoriale=n*fatt(n-1);
01182F92  mov         eax,dword ptr [n] 
01182F95  sub         eax,1 
01182F98  push        eax  
01182F99  call        fatt (11815FAh) 
01182F9E  add         esp,4 
01182FA1  imul        eax,dword ptr [n] 
01182FA5  mov         dword ptr [fattoriale],eax

The multiplication in n*fatt(n-1) is done with imul operation. And its output is available in EAX register.

In first version( with return statement), last two instructions perform the following things. Contents of eax is moved to fattoriale and after that the contents of fattoriale is moved to eax( EAX holds the return value, or result of operation).

In second version( without return statement) the last mov is not found. But the output of iMul is in EAX register and therefore the output will be available to caller function through EAX register.

AlphaDeltaTheta14-Jul-13 17:40

AlphaDeltaTheta

14-Jul-13 17:40

Your explanation is nice but do you expect a beginner in c to understand x86 assembly?

Beauty cannot be defined by abscissas and ordinates; neither are circles and ellipses created by their geometrical formulas.

~ Carl von Clausewitz ~

Source

Joe Woodbury15-Jul-13 10:43

Joe Woodbury

15-Jul-13 10:43

The point is that values are returned in the eax register. The mathematical operation happens to end up with the result in eax AND eax isn't changed by any other operation. Thus it returns the right value. Problem is that something like an inline optimization could change that.

Member 1008957916-Jul-13 6:33

Member 10089579

16-Jul-13 6:33

Thanks to all! Smile | :)

I understood!

Erudite_Eric15-Jul-13 2:35

Erudite_Eric

15-Jul-13 2:35

Without the 'else' the program flow just goes to the end of the func and returns. However there is no return value, so anything calling fatt() and expecting a return value if the 'else' path is hit is going to be dissapointed.

modified 15-Jul-13 9:01am.