C / C++ / MFC

12-Nov-07 23:06

Hi,

I am using a CListCtrl with check boxes for the row (using LVS_EX_CHECKBOXES). Now, my requirement is to use check box in column header of the CListCtrl so that I can "Select All" or "Deselect All" items in list on a single click.

Any help would be appreciated.

Regards,
Paresh.

josip cagalj12-Nov-07 23:56

josip cagalj

12-Nov-07 23:56

Don't mind me, but I do that by placing a button control just under CListCtrl and I place icon (looking like checked box) on it and add some code on 'OnClick' member where I loop through list and set each row as checked. Add another icon button for deselecting all rows.
Glad if I could help!

Paresh Chitte13-Nov-07 0:05

13-Nov-07 0:05

Thanks for your prompt reply.
I am seeking an easier solution for this.

Regards,
Paresh.

David Crow13-Nov-07 3:27

David Crow

13-Nov-07 3:27

Paresh Chitte wrote:
I am seeking an easier solution for this.

What's hard about that? It seemed easy and straight forward to me.

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

_AnsHUMAN_ 12-Nov-07 23:59

_AnsHUMAN_

12-Nov-07 23:59

See Here[^]

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

Paresh Chitte13-Nov-07 0:09

13-Nov-07 0:09

Thanks for your prompt reply.

Regards,
Paresh.

Paresh Chitte19-Nov-07 19:05

19-Nov-07 19:05

Found solution here[^].

Thank you all for your replies.

Regards,
Paresh.

CTreeCtrl problem in MFC

nbugalia12-Nov-07 23:05

nbugalia

12-Nov-07 23:05

The function ItemHasChildren (TreeItem) returns true for a perticular node but GetChildItem (TreeItem) doesnot return a valid node without expanding the node TreeItem. This expanding and shrinking is causing flicker in the tree. Could anyone provide a better solution ?

The sample code is following -

if (ItemHasChildren (TreeItem))
 {
    HTREEITEM tmpTreeItem = TreeItem;
    Expand (tmpTreeItem, TVE_TOGGLE); //Causing flicker

    TreeItem = GetChildItem (TreeItem);
    Expand (tmpTreeItem, TVE_TOGGLE); //Causing flicker
 }

jhwurmbach12-Nov-07 23:49

12-Nov-07 23:49

NishantB++ wrote:
expanding and shrinking is causing flicker in the tree.

Stop the tree from redrawing while you are tampering with it.
From my CTreeView I do:

  GetTreeCtrl().SetRedraw( FALSE);<br />
...<br />
  GetTreeCtrl().SetRedraw( TRUE);

Let's think the unthinkable, let's do the undoable, let's prepare to grapple with the ineffable itself, and see if we may not eff it after all.
Douglas Adams, "Dirk Gently's Holistic Detective Agency"

nbugalia13-Nov-07 1:27

nbugalia

13-Nov-07 1:27

Thanks for your reply.
I have already tried this option, and it is not working.
By the way, have you seen this kind of behaviour that you have to expand the tree first to get the child node, or I am doing something wrong?

jhwurmbach13-Nov-07 1:29

13-Nov-07 1:29

NishantB++ wrote:
expand the tree first to get the child node

I have.
But then I use CWaitingTreeCtrl from Codeproject[^], and there things are much more complicated.

It might really be that the item does not know that it has children and how many of them.

Iain Clarke, Warrior Programmer

Iain Clarke, Warrior Programmer13-Nov-07 2:54

13-Nov-07 2:54

The below code is from MSDN. While their samples can be lacking sometimes, they're not usually wrong.

if (pmyTreeCtrl->ItemHasChildren(hmyItem))
{
   HTREEITEM hNextItem;
   HTREEITEM hChildItem = pmyTreeCtrl->GetChildItem(hmyItem);

   while (hChildItem != NULL)
   {
      hNextItem = pmyTreeCtrl->GetNextItem(hChildItem, TVGN_NEXT);
      pmyTreeCtrl->DeleteItem(hChildItem);
      hChildItem = hNextItem;
   }
}

The only thing I can think of that may mess it up is if your parent item does not actually have children in it, but you've manually set its item.cChildren to I_CHILDRENCALLBACK.

Can you check the return value from ItemHasChildren to make sure it's 0 or 1?

Iain.

how to do dynamic memory allocation for stuct?

neodeaths12-Nov-07 22:50

12-Nov-07 22:50

hi i am new to c programming.

currently i am trying to do dynamic memory allocation to my struct so that i dont have to use a set number of array:

struct person ptr[10];//i dont want this

i have come up to this:

struct person ptr*;

could anyone show me how to do a dynamic memory allocation on struct which can free me of having to state the array size?
i read some ebook saying i could use malloc but so far they used malloc on the string instead of struct.
thanks.

jhwurmbach12-Nov-07 23:46

12-Nov-07 23:46

...define person...

struct person *pPerson; //This is a pointer to a person-struct called pPerson
unsigned int count = 10;

pPerson = malloc( count * sizeof( person));
if( pPersion = NULL)  {
  printf( "Insufficient memory available\n" );
  exit(0);
}

...use pPerson...

free( pPerson);

neodeaths13-Nov-07 5:36

13-Nov-07 5:36

i see where the code is going however could you show me how i shoudl go if i wanted to append to the pointer?

i am thinking if i should create a temp space and reallocated the memory againa dn stores it back in.

how do you think i should do it? and again i would like to say i am doing c programming.

thx

jhwurmbach13-Nov-07 5:45

13-Nov-07 5:45

neodeaths wrote:
i am thinking if i should create a temp space and reallocated the memory againa dn stores it back in.

yes, that is the way to go. But there is a function to do that for you:
Use realloc()

To double the size use

pPerson = realloc( pPerson, 2*count);

pPerson would be changed - be sure to not hold any pointers to the old location.

neodeaths13-Nov-07 5:51

13-Nov-07 5:51

so reallocate would do the work of allocating the new memory i want to use for me? what about the old one do i need to free the memory myself?

also would the reallocated memory contain my old infomation or do i still have to store it away into a temp and put it back?

jhwurmbach13-Nov-07 5:54

13-Nov-07 5:54

Hey, you definitely need to read a book on C ("Brian W. Kernighan, Dennis Ritchie: The C programming language" comes to mind) and MSDN!

neodeaths13-Nov-07 6:03

13-Nov-07 6:03

i read some tutorial on c programming but i wanted to apply dynamic memory allocation on struct rather then string array as i think it is more useful that way.

i guess that dynamic memory array is eassier to learn and maybe i should not jump stright into learning how to do dynamic memory allocation on struct so soon.

jhwurmbach13-Nov-07 6:06

13-Nov-07 6:06

neodeaths wrote:
maybe i should not jump stright into dynamic memory allocation

Maybe.
But in the meantime, just using the information at your fingertips (MS ad in the nineties, shortly after Bill Gates had invented the internet) would suffice:
Look up what MSDN[^] says about realloc[^].

neodeaths13-Nov-07 6:11