SendMessage to Speedup ListView

Abhay Sobti

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Oct 27, 2006, 7:24:04 AM10/27/06

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Hello Everyone,

I know this is a VB forum, but my question pertains to VFP. I am trying to
stop a ListView from redrawing itself as I am inserting 3000 ListItems.
However, the following code does not prevent it from redrawing. Can you
Help?

Abhay Sobti

#DEFINE WM_SETREDRAW 11

DECLARE INTEGER SendMessage IN user32 INTEGER hWnd,;
INTEGER Msg,;
INTEGER wParam,;
INTEGER lParam

=SendMessage(THIS.Lv.hWnd, WM_SETREDRAW ,.T.,0)

** Now I populate the ListBox

=SendMessage(THIS.Lv.hWnd, WM_SETREDRAW ,.F.,0)

AA

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Oct 27, 2006, 8:15:39 AM10/27/06

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Try
Thisform.LockScreen=.T.

-Anders

"Abhay Sobti" <ab...@stansoftware.com> skrev i meddelandet
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Jack Jackson

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Oct 27, 2006, 10:16:58 AM10/27/06

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I don't know about the Listiviw, but with the TreeView setting its
Visible property to .F. speeds it up considerably.

Abhay Sobti

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Oct 28, 2006, 1:34:24 AM10/28/06

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Tried Visible=.F. , and also LockScreen.
Not much affect

Abhay

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AA

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Oct 29, 2006, 11:25:56 AM10/29/06

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If you're working in VFP you can fill a ListBox control with 3000 AddItem or
AddListItem calls in a loop, times the number of columns, or with a single
line setting RecordSource to a multidimensionsl array or to a cursor.
-Anders

"Abhay Sobti" <ab...@stansoftware.com> skrev i meddelandet

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Samir Ibrahim

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Nov 2, 2006, 2:51:53 AM11/2/06

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I have tried this

thisform.listview.visible = .F.
thisform.listview.enable = .F.
* then populate the list view with 100 recoreds * 114 field
thisform.listview.visible = .T.
thisform.listview.enable = .T.

the speed was 2 min 42 sec and after it was 5 sec

Samir ibrahim

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Abhay Sobti

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Nov 3, 2006, 7:12:16 AM11/3/06

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Thanks Samir,

Yes ! There is a difference in speed. But my listview has only 3 columns
with 2000 rows. The difference is not really substantial.

thanks anyway

"Samir Ibrahim" <samir....@wilcopm.com> wrote in message
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Alex.K

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Nov 26, 2006, 9:00:45 PM11/26/06

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Samir,

Try this:

Add a BeginUpdate and a EndUpdate Method to the ListView..
Add new properties WasSorted and ViewStyle

in the PROCEDURE BeginUpdate:
WITH THIS
** To try and speed up the loading process:
** 1) Turn off sorting
** 2) Disable the control
** 3) Change the View style to 3 - List
.Visible = .F.
.WasSorted = .Sorted
.Object.Sorted = .F.
.Object.Enabled = .F.
.ViewStyle = .Object.View
.Object.View = lvwList
SendMessage(.hWnd, WM_SETREDRAW, 0, 0)
LockWindowUpdate(.hWnd)
ENDWITH

in the PROCEDURE EndUpdate:
WITH THIS
.Object.Sorted = .WasSorted
.Object.Enabled = .T.
.Object.View = .ViewStyle
SendMessage(.hWnd, WM_SETREDRAW, 1, 0)
LockWindowUpdate(0)
.Visible = .T.
ENDWITH

The issue the following on loading:

Thisform.yourListView.BeginUpdate

-- Load all your items...

Thisform.yourListView.EndUpdate

FYI: In your SendMessage use integer values for boolean

Hope this helps.

- Alex

Thanks Samir,

thanks anyway