CListCtrl, hide and edit

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From: "Bill Brehm" don't want on 5 May 2008 13:05

---

Joe,

Good point about the zero sized row.

I already provide all the data to the list control via the callback
OnGetdispinfoList(). I set the Owner Data attribute without changing
anything else. Apparently the lParam is no longer stored in the item so my
program displays the first item in each location. I can use the iItem number
instead to solve that and it looks correct. Sorting gives an ASSERT now but
that depends on lParam too so it's not surprising. However, how do I solve
that because I can't get at the iItem number in the compare function.

Also, how do I deal with the number of items in the list control? I could
imagine I just set the size of the list to the total number of items I
should be displaying. It should be fast to do that - the control just
allocates or deallocates memory. Is that correct?

Lastly, is it possible to edit a list control subitem in place? If not, what
is the purpose of EditLabel()? Oh wait. I set Edit Labels. Now I can get an
in place edit of the first column. How can I do the other columns?

Thanks,

Bill


"Joseph M. Newcomer" <newcomer(a)flounder.com> wrote in message
news:g8at14dqekitbjphp1ot3g1f2mpfsogssh(a)4ax.com...
> You can't show/hide elements of a CListBox or CListCtrl. Note that making
> the size 0 will
> just confuse the user who might be using arrow keys to move up and down.
>
> Look into virtual listboxes or virtual list controls. You don't need to
> keep re-adding
> everything
> joe
>
> On Mon, 5 May 2008 07:28:29 +0800, "Bill Brehm" <don't want spam> wrote:
>
>>Dave,
>>
>>Your idea was my plan B. Problem is I have a lot of items in my list so
>>deleting everything out and re-adding everything takes quite some time.
>>That's why I was looking for a plan A. Are you saying I guess that there
>>is
>>no way to hide items or size a row?
>>
>>Is there a way to edit in place?
>>
>>Thanks,
>>
>>Bill
>>
>>
>>"David Webber" <dave(a)musical-dot-demon-dot-co.uk> wrote in message
>>news:eJ9gLqgrIHA.5096(a)TK2MSFTNGP02.phx.gbl...
>>>
>>> "Bill Brehm" <don't want spam> wrote in message
>>> news:OFHl1RfrIHA.4544(a)TK2MSFTNGP04.phx.gbl...
>>>
>>>> MFC 6.0. The Help implied that I can hide an item in a CListCtrl. But I
>>>> can't find out how to do it. I'd like to be able to fill a CListCtrl
>>>> with
>>>> a set of data, then filter to show only a subset by hiding all those
>>>> items not in the subset.
>>>>
>>>> Also, GetEditControl() implies (to me at least) that I can get a CEdit
>>>> pointer edit an item (or subitem?) in a CListCtrl. But I can't see how
>>>> to
>>>> specify the item or subitem to be edited. I have a different CListCtrl
>>>> with a number of items that I would like to edit in place to allow the
>>>> user to configure something.
>>>>
>>>> Thanks for any suggestions.
>>>
>>> In circumstances like this I
>>>
>>> - derive my own class from CListBox
>>> - store in it a collection of ALL objects which can be selected (usually
>>> in a vector)
>>> - add to the list box only those which need to be seen.
>>> - in particular I put the text I want to show in the list item, and
>>> store
>>> a pointer to the corresponding object as the list item's data.
>>>
>>> When the set of objects I want to show changes, I
>>>
>>> - empty everything out of the list,
>>> - add the new set of objects I want to show in the same way.
>>>
>>> HTH
>>>
>>> Dave
>>> --
>>> David Webber
>>> Author of 'Mozart the Music Processor'
>>> http://www.mozart.co.uk
>>> For discussion/support see
>>> http://www.mozart.co.uk/mozartists/mailinglist.htm
>>>
>>>
>>
> Joseph M. Newcomer [MVP]
> email: newcomer(a)flounder.com
> Web: http://www.flounder.com
> MVP Tips: http://www.flounder.com/mvp_tips.htm

From: Joseph M. Newcomer on 5 May 2008 14:54

---

See below..
On Tue, 6 May 2008 01:05:01 +0800, "Bill Brehm" <don't want spam> wrote:

>Joe,
>
>Good point about the zero sized row.
>
>I already provide all the data to the list control via the callback
>OnGetdispinfoList(). I set the Owner Data attribute without changing
>anything else. Apparently the lParam is no longer stored in the item
****
In a virtual control, indeed, there is no data storage at all.
****
>program displays the first item in each location. I can use the iItem number
>instead to solve that and it looks correct. Sorting gives an ASSERT now but
>that depends on lParam too so it's not surprising. However, how do I solve
>that because I can't get at the iItem number in the compare function.
****
Tom Serface is our virtual-CListCtrl guru, perhaps he can answer this. I've not used
virtual controls because I typically have a small number of items to store, and there are
only a few cases where I *should* have used one, but because it was not a "product
deliverable" but a personal hobby project, I didn't bother.
****
>
>Also, how do I deal with the number of items in the list control? I could
>imagine I just set the size of the list to the total number of items I
>should be displaying. It should be fast to do that - the control just
>allocates or deallocates memory. Is that correct?
****
For a virtual control, there is no allocation at all, which is why you get the
performance.
***
>
>Lastly, is it possible to edit a list control subitem in place? If not, what
>is the purpose of EditLabel()? Oh wait. I set Edit Labels. Now I can get an
>in place edit of the first column. How can I do the other columns?
****
Due to fundamental failures of design, a CListCtrl only allows the editing of the 0th
elment, making it nearly useless for anything that has sophisiticated constraints (for
example, I'd like the 0th element to be the index, but now I have to get into manipulating
the column order to make the one-and-only-editable-field be the logical column 0 while
displaying some other column in the leftmost position, a real pain). I think there are
some articles in www.codeproject.com on creating a CListCtrl subclass in which any column
can be edited, and I would consider looking there first.
joe
****
>
>Thanks,
>
>Bill
>
>
>"Joseph M. Newcomer" <newcomer(a)flounder.com> wrote in message
>news:g8at14dqekitbjphp1ot3g1f2mpfsogssh(a)4ax.com...
>> You can't show/hide elements of a CListBox or CListCtrl. Note that making
>> the size 0 will
>> just confuse the user who might be using arrow keys to move up and down.
>>
>> Look into virtual listboxes or virtual list controls. You don't need to
>> keep re-adding
>> everything
>> joe
>>
>> On Mon, 5 May 2008 07:28:29 +0800, "Bill Brehm" <don't want spam> wrote:
>>
>>>Dave,
>>>
>>>Your idea was my plan B. Problem is I have a lot of items in my list so
>>>deleting everything out and re-adding everything takes quite some time.
>>>That's why I was looking for a plan A. Are you saying I guess that there
>>>is
>>>no way to hide items or size a row?
>>>
>>>Is there a way to edit in place?
>>>
>>>Thanks,
>>>
>>>Bill
>>>
>>>
>>>"David Webber" <dave(a)musical-dot-demon-dot-co.uk> wrote in message
>>>news:eJ9gLqgrIHA.5096(a)TK2MSFTNGP02.phx.gbl...
>>>>
>>>> "Bill Brehm" <don't want spam> wrote in message
>>>> news:OFHl1RfrIHA.4544(a)TK2MSFTNGP04.phx.gbl...
>>>>
>>>>> MFC 6.0. The Help implied that I can hide an item in a CListCtrl. But I
>>>>> can't find out how to do it. I'd like to be able to fill a CListCtrl
>>>>> with
>>>>> a set of data, then filter to show only a subset by hiding all those
>>>>> items not in the subset.
>>>>>
>>>>> Also, GetEditControl() implies (to me at least) that I can get a CEdit
>>>>> pointer edit an item (or subitem?) in a CListCtrl. But I can't see how
>>>>> to
>>>>> specify the item or subitem to be edited. I have a different CListCtrl
>>>>> with a number of items that I would like to edit in place to allow the
>>>>> user to configure something.
>>>>>
>>>>> Thanks for any suggestions.
>>>>
>>>> In circumstances like this I
>>>>
>>>> - derive my own class from CListBox
>>>> - store in it a collection of ALL objects which can be selected (usually
>>>> in a vector)
>>>> - add to the list box only those which need to be seen.
>>>> - in particular I put the text I want to show in the list item, and
>>>> store
>>>> a pointer to the corresponding object as the list item's data.
>>>>
>>>> When the set of objects I want to show changes, I
>>>>
>>>> - empty everything out of the list,
>>>> - add the new set of objects I want to show in the same way.
>>>>
>>>> HTH
>>>>
>>>> Dave
>>>> --
>>>> David Webber
>>>> Author of 'Mozart the Music Processor'
>>>> http://www.mozart.co.uk
>>>> For discussion/support see
>>>> http://www.mozart.co.uk/mozartists/mailinglist.htm
>>>>
>>>>
>>>
>> Joseph M. Newcomer [MVP]
>> email: newcomer(a)flounder.com
>> Web: http://www.flounder.com
>> MVP Tips: http://www.flounder.com/mvp_tips.htm
>
Joseph M. Newcomer [MVP]
email: newcomer(a)flounder.com
Web: http://www.flounder.com
MVP Tips: http://www.flounder.com/mvp_tips.htm

From: Tom Serface on 5 May 2008 16:03

---

I typically sort the items in my memory list (the one the list control is
calling on to get it's value line by line). Of course the memory list can
be just about anything, but for me it's typically a vector of CObList of
objects so sorting is usually based off of one of the items in the object.
For example, I typically have a list of items that I just call a routine on
like:

bool CDialogWithList::CompareAndSwapString1(int pos, bool bAscending)
{
CMyObjectInfo *temp;
int posFirst = pos;
int posNext = pos + 1;

if(!bAscending) {
if (((CMyObjectInfo *)GetAt(posFirst))->m_csString1 <
((CMyObjectInfo *)GetAt(posNext))->m_csString1) {
temp = (CMyObjectInfo *)GetAt(posFirst);
SetAt(posFirst, GetAt(posNext));
SetAt(posNext, temp);
return TRUE;
}
}
else if (((CMyObjectInfo *)GetAt(posFirst))->m_csString1 >
((CMyObjectInfo *)GetAt(posNext))->m_csString1) {
temp = (CMyObjectInfo *)GetAt(posFirst);
SetAt(posFirst, GetAt(posNext));
SetAt(posNext, temp);
return TRUE;
}
return FALSE;
}

bool CDataFileArray::CompareAndSwapDate(int pos, bool bAscending)
{
CMyObjectInfo *temp;
int posFirst = pos;
int posNext = pos + 1;
if(!bAscending) {
if (((CMyObjectInfo *)GetAt(posFirst))->m_cDate <
((CMyObjectInfo *)GetAt(posNext))->m_cDate) {
temp = (CMyObjectInfo *)GetAt(posFirst);
SetAt(posFirst, GetAt(posNext));
SetAt(posNext, temp);
return TRUE;
}
}
else if (((CMyObjectInfo *)GetAt(posFirst))->m_cDate >
((CMyObjectInfo *)GetAt(posNext))->m_cDate) {
temp = (CMyObjectInfo *)GetAt(posFirst);
SetAt(posFirst, GetAt(posNext));
SetAt(posNext, temp);
return TRUE;
}
return FALSE;
}

Then I call a routine to Sort the object list like:

void CMyDialogWithList::Sort(MY_DATA_SORT_ITEMS nSort, bool bAscending)
{
bool bNotDone = TRUE;
int pos = 0;

while (bNotDone) {
bNotDone = FALSE;
switch(nSort) {
case MY_DATA_SORT_NONE:
break;
case MY_DATA_SORT_STRING1:
for(pos = 0;pos < GetUpperBound();pos++)
bNotDone |= CompareAndSwapString1(pos, bAscending);
break;
case MY_DATA_SORT_STRING2:
for(pos = 0;pos < GetUpperBound();pos++)
bNotDone |= CompareAndSwapString2(pos, bAscending);
break;
case MY_DATA_SORT_DATE:
for(pos = 0;pos < GetUpperBound();pos++)
bNotDone |= CompareAndSwapDate(pos, bAscending);
break;
default:
break;
};
}
}

So I don't use the sort mechanism in the list control at all. When the
column wants to sort I just sort the list then refresh the current screen
and only the items on the screen are drawn. I also move it back to the top
of the list when someone sorts one of the columns. I think is sort of
expected behavior. This is may not be the most efficient method for doing
sorting, but it works well and keeps the object list in an order that I can
write out and read back in the same order as the user last sorted.

Also, you can edit sub-items, but you have create your own edit control or
trick it into think it is colums 0. For example:

http://www.codeguru.com/cpp/controls/listview/editingitemsandsubitem/article.php/c4175/

It's not that difficult once you get it implemented.

Tom

"Joseph M. Newcomer" <newcomer(a)flounder.com> wrote in message
news:cllu14ti1a6i5oebn448d47l9rpbga6gfs(a)4ax.com...
> See below..

>>program displays the first item in each location. I can use the iItem
>>number
>>instead to solve that and it looks correct. Sorting gives an ASSERT now
>>but
>>that depends on lParam too so it's not surprising. However, how do I solve
>>that because I can't get at the iItem number in the compare function.
> ****
> Tom Serface is our virtual-CListCtrl guru, perhaps he can answer this.
> I've not used
> virtual controls because I typically have a small number of items to
> store, and there are
> only a few cases where I *should* have used one, but because it was not a
> "product
> deliverable" but a personal hobby project, I didn't bother.
> ****
>>
>>Also, how do I deal with the number of items in the list control? I could
>>imagine I just set the size of the list to the total number of items I
>>should be displaying. It should be fast to do that - the control just
>>allocates or deallocates memory. Is that correct?
> ****
> For a virtual control, there is no allocation at all, which is why you get
> the
> performance.
> ***
>>
>>Lastly, is it possible to edit a list control subitem in place? If not,
>>what
>>is the purpose of EditLabel()? Oh wait. I set Edit Labels. Now I can get
>>an
>>in place edit of the first column. How can I do the other columns?
> ****
> Due to fundamental failures of design, a CListCtrl only allows the editing
> of the 0th
> elment, making it nearly useless for anything that has sophisiticated
> constraints (for
> example, I'd like the 0th element to be the index, but now I have to get
> into manipulating
> the column order to make the one-and-only-editable-field be the logical
> column 0 while
> displaying some other column in the leftmost position, a real pain). I
> think there are
> some articles in www.codeproject.com on creating a CListCtrl subclass in
> which any column
> can be edited, and I would consider looking there first.
> joe
> ****

From: "Bill Brehm" don't want on 5 May 2008 20:32

---

Thanks Joe and Tom. I think I have all I need to proceed.

"Tom Serface" <tom.nospam(a)camaswood.com> wrote in message
news:EE4BFD17-0635-434D-BDE3-6AF0603E1E05(a)microsoft.com...
>I typically sort the items in my memory list (the one the list control is
>calling on to get it's value line by line). Of course the memory list can
>be just about anything, but for me it's typically a vector of CObList of
>objects so sorting is usually based off of one of the items in the object.
>For example, I typically have a list of items that I just call a routine on
>like:
>
> bool CDialogWithList::CompareAndSwapString1(int pos, bool bAscending)
> {
> CMyObjectInfo *temp;
> int posFirst = pos;
> int posNext = pos + 1;
>
> if(!bAscending) {
> if (((CMyObjectInfo *)GetAt(posFirst))->m_csString1 <
> ((CMyObjectInfo *)GetAt(posNext))->m_csString1) {
> temp = (CMyObjectInfo *)GetAt(posFirst);
> SetAt(posFirst, GetAt(posNext));
> SetAt(posNext, temp);
> return TRUE;
> }
> }
> else if (((CMyObjectInfo *)GetAt(posFirst))->m_csString1 >
> ((CMyObjectInfo *)GetAt(posNext))->m_csString1) {
> temp = (CMyObjectInfo *)GetAt(posFirst);
> SetAt(posFirst, GetAt(posNext));
> SetAt(posNext, temp);
> return TRUE;
> }
> return FALSE;
> }
>
> bool CDataFileArray::CompareAndSwapDate(int pos, bool bAscending)
> {
> CMyObjectInfo *temp;
> int posFirst = pos;
> int posNext = pos + 1;
> if(!bAscending) {
> if (((CMyObjectInfo *)GetAt(posFirst))->m_cDate <
> ((CMyObjectInfo *)GetAt(posNext))->m_cDate) {
> temp = (CMyObjectInfo *)GetAt(posFirst);
> SetAt(posFirst, GetAt(posNext));
> SetAt(posNext, temp);
> return TRUE;
> }
> }
> else if (((CMyObjectInfo *)GetAt(posFirst))->m_cDate >
> ((CMyObjectInfo *)GetAt(posNext))->m_cDate) {
> temp = (CMyObjectInfo *)GetAt(posFirst);
> SetAt(posFirst, GetAt(posNext));
> SetAt(posNext, temp);
> return TRUE;
> }
> return FALSE;
> }
>
> Then I call a routine to Sort the object list like:
>
> void CMyDialogWithList::Sort(MY_DATA_SORT_ITEMS nSort, bool bAscending)
> {
> bool bNotDone = TRUE;
> int pos = 0;
>
> while (bNotDone) {
> bNotDone = FALSE;
> switch(nSort) {
> case MY_DATA_SORT_NONE:
> break;
> case MY_DATA_SORT_STRING1:
> for(pos = 0;pos < GetUpperBound();pos++)
> bNotDone |= CompareAndSwapString1(pos, bAscending);
> break;
> case MY_DATA_SORT_STRING2:
> for(pos = 0;pos < GetUpperBound();pos++)
> bNotDone |= CompareAndSwapString2(pos, bAscending);
> break;
> case MY_DATA_SORT_DATE:
> for(pos = 0;pos < GetUpperBound();pos++)
> bNotDone |= CompareAndSwapDate(pos, bAscending);
> break;
> default:
> break;
> };
> }
> }
>
> So I don't use the sort mechanism in the list control at all. When the
> column wants to sort I just sort the list then refresh the current screen
> and only the items on the screen are drawn. I also move it back to the
> top of the list when someone sorts one of the columns. I think is sort of
> expected behavior. This is may not be the most efficient method for doing
> sorting, but it works well and keeps the object list in an order that I
> can write out and read back in the same order as the user last sorted.
>
> Also, you can edit sub-items, but you have create your own edit control or
> trick it into think it is colums 0. For example:
>
> http://www.codeguru.com/cpp/controls/listview/editingitemsandsubitem/article.php/c4175/
>
> It's not that difficult once you get it implemented.
>
> Tom
>
> "Joseph M. Newcomer" <newcomer(a)flounder.com> wrote in message
> news:cllu14ti1a6i5oebn448d47l9rpbga6gfs(a)4ax.com...
>> See below..
>
>>>program displays the first item in each location. I can use the iItem
>>>number
>>>instead to solve that and it looks correct. Sorting gives an ASSERT now
>>>but
>>>that depends on lParam too so it's not surprising. However, how do I
>>>solve
>>>that because I can't get at the iItem number in the compare function.
>> ****
>> Tom Serface is our virtual-CListCtrl guru, perhaps he can answer this.
>> I've not used
>> virtual controls because I typically have a small number of items to
>> store, and there are
>> only a few cases where I *should* have used one, but because it was not a
>> "product
>> deliverable" but a personal hobby project, I didn't bother.
>> ****
>>>
>>>Also, how do I deal with the number of items in the list control? I could
>>>imagine I just set the size of the list to the total number of items I
>>>should be displaying. It should be fast to do that - the control just
>>>allocates or deallocates memory. Is that correct?
>> ****
>> For a virtual control, there is no allocation at all, which is why you
>> get the
>> performance.
>> ***
>>>
>>>Lastly, is it possible to edit a list control subitem in place? If not,
>>>what
>>>is the purpose of EditLabel()? Oh wait. I set Edit Labels. Now I can get
>>>an
>>>in place edit of the first column. How can I do the other columns?
>> ****
>> Due to fundamental failures of design, a CListCtrl only allows the
>> editing of the 0th
>> elment, making it nearly useless for anything that has sophisiticated
>> constraints (for
>> example, I'd like the 0th element to be the index, but now I have to get
>> into manipulating
>> the column order to make the one-and-only-editable-field be the logical
>> column 0 while
>> displaying some other column in the leftmost position, a real pain). I
>> think there are
>> some articles in www.codeproject.com on creating a CListCtrl subclass in
>> which any column
>> can be edited, and I would consider looking there first.
>> joe
>> ****
>

From: Joseph M. Newcomer on 5 May 2008 23:26

---

Looks like n**2 bubble sort. Works OK for small n, but for large n, it is a killer. I
tend to just use qsort because it is n*log(n)

I once had an app which required sorting a doubly-linked list. The problem was that old
data files were unsorted. So what I did was for any version of the file < k (the version
k was the one that now required the list be maintained in ascending order, for realtime
performance), I would run across the list once; if it was in order, I left it alone.

If it was not in order, I allocated a vector of count-of-list-elements pointers, put a
pointer to every list element in it, qsorted the array, then ran through the array,
linking up the elements in sorted order. This whole operation took under 5 seconds on an
80286 (read: small memory). The problem was that for very large arrays, we discovered in
beta testing, when I did the malloc(n * sizeof(void *)), I got back NULL because there
wasn't enough space to allocate the side vector. In that case, I popped up a status
display saying "Updating older format file to new format, please be patient, this may take
several minutes" and proceeded to do a bubble sort, which could take up to three minutes.
Of course, once we wrote the file back out in the new format, we knew it was in order and
didn't have to go through this again.

But it really pointed out how n**2 and n*log2(n) differ in performance.
joe

On Mon, 5 May 2008 13:03:38 -0700, "Tom Serface" <tom.nospam(a)camaswood.com> wrote:

>I typically sort the items in my memory list (the one the list control is
>calling on to get it's value line by line). Of course the memory list can
>be just about anything, but for me it's typically a vector of CObList of
>objects so sorting is usually based off of one of the items in the object.
>For example, I typically have a list of items that I just call a routine on
>like:
>
>bool CDialogWithList::CompareAndSwapString1(int pos, bool bAscending)
>{
> CMyObjectInfo *temp;
> int posFirst = pos;
> int posNext = pos + 1;
>
> if(!bAscending) {
> if (((CMyObjectInfo *)GetAt(posFirst))->m_csString1 <
> ((CMyObjectInfo *)GetAt(posNext))->m_csString1) {
> temp = (CMyObjectInfo *)GetAt(posFirst);
> SetAt(posFirst, GetAt(posNext));
> SetAt(posNext, temp);
> return TRUE;
> }
> }
> else if (((CMyObjectInfo *)GetAt(posFirst))->m_csString1 >
> ((CMyObjectInfo *)GetAt(posNext))->m_csString1) {
> temp = (CMyObjectInfo *)GetAt(posFirst);
> SetAt(posFirst, GetAt(posNext));
> SetAt(posNext, temp);
> return TRUE;
> }
> return FALSE;
>}
>
>bool CDataFileArray::CompareAndSwapDate(int pos, bool bAscending)
>{
> CMyObjectInfo *temp;
> int posFirst = pos;
> int posNext = pos + 1;
> if(!bAscending) {
> if (((CMyObjectInfo *)GetAt(posFirst))->m_cDate <
> ((CMyObjectInfo *)GetAt(posNext))->m_cDate) {
> temp = (CMyObjectInfo *)GetAt(posFirst);
> SetAt(posFirst, GetAt(posNext));
> SetAt(posNext, temp);
> return TRUE;
> }
> }
> else if (((CMyObjectInfo *)GetAt(posFirst))->m_cDate >
> ((CMyObjectInfo *)GetAt(posNext))->m_cDate) {
> temp = (CMyObjectInfo *)GetAt(posFirst);
> SetAt(posFirst, GetAt(posNext));
> SetAt(posNext, temp);
> return TRUE;
> }
> return FALSE;
>}
>
>Then I call a routine to Sort the object list like:
>
>void CMyDialogWithList::Sort(MY_DATA_SORT_ITEMS nSort, bool bAscending)
>{
> bool bNotDone = TRUE;
> int pos = 0;
>
> while (bNotDone) {
> bNotDone = FALSE;
> switch(nSort) {
> case MY_DATA_SORT_NONE:
> break;
> case MY_DATA_SORT_STRING1:
> for(pos = 0;pos < GetUpperBound();pos++)
> bNotDone |= CompareAndSwapString1(pos, bAscending);
> break;
> case MY_DATA_SORT_STRING2:
> for(pos = 0;pos < GetUpperBound();pos++)
> bNotDone |= CompareAndSwapString2(pos, bAscending);
> break;
> case MY_DATA_SORT_DATE:
> for(pos = 0;pos < GetUpperBound();pos++)
> bNotDone |= CompareAndSwapDate(pos, bAscending);
> break;
> default:
> break;
> };
> }
>}
>
>So I don't use the sort mechanism in the list control at all. When the
>column wants to sort I just sort the list then refresh the current screen
>and only the items on the screen are drawn. I also move it back to the top
>of the list when someone sorts one of the columns. I think is sort of
>expected behavior. This is may not be the most efficient method for doing
>sorting, but it works well and keeps the object list in an order that I can
>write out and read back in the same order as the user last sorted.
>
>Also, you can edit sub-items, but you have create your own edit control or
>trick it into think it is colums 0. For example:
>
>http://www.codeguru.com/cpp/controls/listview/editingitemsandsubitem/article.php/c4175/
>
>It's not that difficult once you get it implemented.
>
>Tom
>
>"Joseph M. Newcomer" <newcomer(a)flounder.com> wrote in message
>news:cllu14ti1a6i5oebn448d47l9rpbga6gfs(a)4ax.com...
>> See below..
>
>>>program displays the first item in each location. I can use the iItem
>>>number
>>>instead to solve that and it looks correct. Sorting gives an ASSERT now
>>>but
>>>that depends on lParam too so it's not surprising. However, how do I solve
>>>that because I can't get at the iItem number in the compare function.
>> ****
>> Tom Serface is our virtual-CListCtrl guru, perhaps he can answer this.
>> I've not used
>> virtual controls because I typically have a small number of items to
>> store, and there are
>> only a few cases where I *should* have used one, but because it was not a
>> "product
>> deliverable" but a personal hobby project, I didn't bother.
>> ****
>>>
>>>Also, how do I deal with the number of items in the list control? I could
>>>imagine I just set the size of the list to the total number of items I
>>>should be displaying. It should be fast to do that - the control just
>>>allocates or deallocates memory. Is that correct?
>> ****
>> For a virtual control, there is no allocation at all, which is why you get
>> the
>> performance.
>> ***
>>>
>>>Lastly, is it possible to edit a list control subitem in place? If not,
>>>what
>>>is the purpose of EditLabel()? Oh wait. I set Edit Labels. Now I can get
>>>an
>>>in place edit of the first column. How can I do the other columns?
>> ****
>> Due to fundamental failures of design, a CListCtrl only allows the editing
>> of the 0th
>> elment, making it nearly useless for anything that has sophisiticated
>> constraints (for
>> example, I'd like the 0th element to be the index, but now I have to get
>> into manipulating
>> the column order to make the one-and-only-editable-field be the logical
>> column 0 while
>> displaying some other column in the leftmost position, a real pain). I
>> think there are
>> some articles in www.codeproject.com on creating a CListCtrl subclass in
>> which any column
>> can be edited, and I would consider looking there first.
>> joe
>> ****
Joseph M. Newcomer [MVP]
email: newcomer(a)flounder.com
Web: http://www.flounder.com
MVP Tips: http://www.flounder.com/mvp_tips.htm

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