Codejock Developer Community : Performance problem when deleting items from grid

Performance problem when deleting items from grid : Hi Oleg,your are right: The code...

Tue, 08 Jan 2008 10:19:24 +0000

Author: farr02
Subject: 9211
Posted: 08 January 2008 at 10:19am

Hi Oleg,

your are right: The code works fine.
Thank you very much.

Bye
Holger

Performance problem when deleting items from grid : Hi, Last version to try: :) void...

Tue, 08 Jan 2008 02:03:32 +0000

Author: Oleg
Subject: 9211
Posted: 08 January 2008 at 2:03am

Hi,

Last version to try: :)

void BeginUpdate()
{
GetGridView().m_nLockUpdate = 1;
GetGridView().SetRedraw(FALSE);

GetGridView().().ResetContent();
}

void EndUpdate()
{
GetGridView().m_nLockUpdate = 0;
GetGridView().SetRedraw(TRUE);

Refresh();
}

Think it will work fine.

Performance problem when deleting items from grid : Hello Oleg,doesn't work either:-(I...

Mon, 07 Jan 2008 04:50:20 +0000

Author: farr02
Subject: 9211
Posted: 07 January 2008 at 4:50am

Hello Oleg,

doesn't work either:-(
I uploaded two files regarding the access violation: Number one ( uploads/20080107_042735_CJ_Fhut.zip ) is a crash dump file saved with WinDbg (WinDbg command: .dump /mFhut CJ_Fhut.dmp) and the second ( uploads/20080107_043556_ProblemItemRemo.zip )gives you a small description of the functions I inserted to the lib, and some more information about the access violation.

Hope it helps.
Bye
Holger

Performance problem when deleting items from grid : Hi, Think also you need call...

Fri, 04 Jan 2008 08:36:38 +0000

Author: Oleg
Subject: 9211
Posted: 04 January 2008 at 8:36am

Hi,

Think also you need call Refresh() in the end. (after SetRedraw(FALSE))

Performance problem when deleting items from grid : Hi Oleg,doesn't work It leads...

Fri, 04 Jan 2008 06:21:46 +0000

Author: farr02
Subject: 9211
Posted: 04 January 2008 at 6:21am

Hi Oleg,
doesn't work
It leads to an access violation in CXTPPropertyGridView::_RefreshIndexes(). I have tried to eliminate the call to Refresh in the CXTPPropertyGridItem::Remove function but that gives me other errors.
So I think for the moment it is the best to stay with the current situation and hope for one of the next releases. Or do you have a better idea?

Thank you yery much.
Bye
Holger

Performance problem when deleting items from grid : oh, right, it deletes content. ok,...

Thu, 03 Jan 2008 11:18:26 +0000

Author: Oleg
Subject: 9211
Posted: 03 January 2008 at 11:18am

oh, right, it deletes content.

ok, try this

wndGrid.GetGridView().m_nLockUpdate = 1;
wndGrid.GetGridView().SetRedraw(FALSE);

wndGrid.GetGridView().m_nLockUpdate = 0;
wndGrid.GetGridView().SetRedraw(FALSE);

Performance problem when deleting items from grid : Hello Oleg,I have already made...

Thu, 03 Jan 2008 10:41:46 +0000

Author: farr02
Subject: 9211
Posted: 03 January 2008 at 10:41am

Hello Oleg,

I have already made some testing with Begin/EndUpdate before. When I just put them around the while-loop in the above code, the result is an empty grid. As far as I understood (please correct me if I am wrong) BeginUpdate stores some information about some grid states, disables refresh and redraw and finally deletes the whole grid. EndUpdate restores the saved states, enables refresh and redraw and then redraws the grid. That means I have to rebuild my whole dialog inside a Begin/EndUpdate-block instead of just inserting or deleting a number of items into resp. from the existing dialog.

Maybe this is an item for the wish-list:
Implement a function that locks grid refreshing and redrawing during a bunch of insertion or removal operations without the need to rebuild the whole dialog.

Bye
Holger

PS: I have forgotten in my first post: Happy New Year!

Performance problem when deleting items from grid : Hi, There are BeginUpdate,...

Thu, 03 Jan 2008 06:57:12 +0000

Author: Oleg
Subject: 9211
Posted: 03 January 2008 at 6:57am

Hi,

There are BeginUpdate, EndUpdate methods.

call them before/after your loop.

Performance problem when deleting items from grid : Hello,in my application I noticed...

Thu, 03 Jan 2008 04:00:18 +0000

Author: farr02
Subject: 9211
Posted: 03 January 2008 at 4:00am

Hello,
in my application I noticed a performance problem when deleting a large number of elements from the grid via pItem->Remove();
Example:
First I create a large number of categories each holds two items:

CString sCatName;
g_pCustom = m_wndPropertyGrid.AddCategory(_T("Long Dialog"));
for(int i = 0; i < 512; ++i)
{
    sCatName.Format(_T("Category %03d"), i);
    CXTPPropertyGridItem* pCat = 
        g_pCustom->AddChildItem(new CXTPPropertyGridItemCategory(sCatName));
    pCat->AddChildItem(new CXTPPropertyGridItemNumber(_T("Element 1"), i));
    pCat->AddChildItem(new CXTPPropertyGridItemNumber(_T("Element 2"), i));
    pCat->Expand();
}
g_pCustom->Expand();

Then I delete 'Element 1' in every category using the following code:

if(g_pCustom)
{
    CXTPPropertyGridItems* pItems = g_pCustom->GetChilds();
    if(pItems)
    {
        int i = pItems->GetCount() - 1;
        while (i >= 0)
        {
            CXTPPropertyGridItem* pCategory = pItems->GetAt(i);
            if(pCategory)
            {
                CXTPPropertyGridItems* pElements = pCategory->GetChilds();
                if(pElements)
                {
                    CXTPPropertyGridItem* pElement1 = pElements->GetAt(0);
                    if(pElement1)
                    {
                        // here 'Element 1' will be deleted
                        pElement1->Remove();
                        pElement1 = 0;
                    }
                }
            }
            --i;
        }
    }
}

The removal of the elements takes more than a minute in release configuration on a 3 GHz computer running Win XP and ToolkitPro v9.81, whereas creation time is less than a second.
Is something wrong with my code or takes the remove-function so much time?
(I think the problem may be the call to m_pGrid->Refresh(); in the remove function.)
How can I speed up the removal?

Bye
Holger