Are ListViews really slow?

[TryingLikeHeck]

I have an application that uses a LIstView.
Maybe 100 items each with 20 subitems.

The app looks at eack item and subitem twice.
I.e., it scans the entire set of data
item1, sub1,sub2,...
item2,sub1,sub2 ...
..
..
twice

I've never run it long enough for it to complete.
I'm using 3GHz CPU on an XPS by Dell

Could it be that accessing a ListView takes that long?

Thanks for any help

[Mike Bulava]

Let see some code for populating the Listview.

Or Maybe you want to put a BeginEdit before you start adding items and an
EndEdit when your done that will help speed it up a little.

"TryingLikeHeck " <tr************ @aol.com> wrote in message
news:20******** *************** ****@mb-m16.aol.com...

I have an application that uses a LIstView.
Maybe 100 items each with 20 subitems.

The app looks at eack item and subitem twice.
I.e., it scans the entire set of data
item1, sub1,sub2,...
item2,sub1,sub2 ...
.
.
twice

I've never run it long enough for it to complete.
I'm using 3GHz CPU on an XPS by Dell

Could it be that accessing a ListView takes that long?

Thanks for any help

[Jerry Ham]

Sounds like something in your code.

I've currently got a project with a listview for Active Directory Domain
controllers and properties (properties in the subitems). In our domain,
there are currently 145 DC, so 145 listview items, each with 5 subitems. I
don't see any slowness there at all.

Jerry

"TryingLikeHeck " <tr************ @aol.com> wrote in message
news:20******** *************** ****@mb-m16.aol.com...

I have an application that uses a LIstView.
Maybe 100 items each with 20 subitems.

The app looks at eack item and subitem twice.
I.e., it scans the entire set of data
item1, sub1,sub2,...
item2,sub1,sub2 ...
.
.
twice

I've never run it long enough for it to complete.
I'm using 3GHz CPU on an XPS by Dell

Could it be that accessing a ListView takes that long?

Thanks for any help

[CJ Taylor]

I wouldn't access the ListView itself, but the datasource the you loaded it
from. That or just search the index of the listview. By default, you
really shouldn't use any sort of UI for your business logic

=CJ
"TryingLikeHeck " <tr************ @aol.com> wrote in message
news:20******** *************** ****@mb-m16.aol.com...

I have an application that uses a LIstView.
Maybe 100 items each with 20 subitems.

The app looks at eack item and subitem twice.
I.e., it scans the entire set of data
item1, sub1,sub2,...
item2,sub1,sub2 ...
.
.
twice

I've never run it long enough for it to complete.
I'm using 3GHz CPU on an XPS by Dell

Could it be that accessing a ListView takes that long?

Thanks for any help

[Armin Zingler]

"TryingLikeHeck " <tr************ @aol.com> schrieb

I have an application that uses a LIstView.
Maybe 100 items each with 20 subitems.

The app looks at eack item and subitem twice.
I.e., it scans the entire set of data
item1, sub1,sub2,...
item2,sub1,sub2 ...
.
.
twice

I've never run it long enough for it to complete.
I'm using 3GHz CPU on an XPS by Dell

Could it be that accessing a ListView takes that long?

Code?
--
Armin

http://www.plig.net/nnq/nquote.html
http://www.netmeister.org/news/learn2quote.html

[CJ Taylor]

You have 145 Domain Controllers???
"Jerry Ham" <No*****@Sompla ce.net> wrote in message
news:%2******** ********@tk2msf tngp13.phx.gbl. ..

Sounds like something in your code.

I've currently got a project with a listview for Active Directory Domain
controllers and properties (properties in the subitems). In our domain,
there are currently 145 DC, so 145 listview items, each with 5 subitems. I
don't see any slowness there at all.

Jerry

"TryingLikeHeck " <tr************ @aol.com> wrote in message
news:20******** *************** ****@mb-m16.aol.com...

I have an application that uses a LIstView.
Maybe 100 items each with 20 subitems.

The app looks at eack item and subitem twice.
I.e., it scans the entire set of data
item1, sub1,sub2,...
item2,sub1,sub2 ...
.
.
twice

I've never run it long enough for it to complete.
I'm using 3GHz CPU on an XPS by Dell

Could it be that accessing a ListView takes that long?

Thanks for any help

[paul]

I have noticed the same thing. I also have an app that
can have well over a couple of thousand ListViewItems and
it is really slow to draw. I use the AddRange function
to do all the drawing but there isnt much difference from
just using the simple Add(). My code looks like this:

For idx = 0 To theFile.TestDat aProp.PtrDataPr op.Length - 1
elements(idx) = New ListViewItem
theFile.TestDat aProp.
PtrDataProp(idx ).DataProp)
Next
theFile.form.Dr awGrid(elements ,
theFile.form.Li stViewDataProp( ))

Public Sub DrawGrid(ByRef ele() As ListViewItem, ByRef
grid As ListView)
grid.Items.AddR ange(ele)
End Sub

could it be all that access of the form. I sort of
inherited the code base so i kept the basic structure i
was given

-paul

-----Original Message-----
Let see some code for populating the Listview.

Or Maybe you want to put a BeginEdit before you start adding items and anEndEdit when your done that will help speed it up a little.
"TryingLikeHec k" <tr************ @aol.com> wrote in messagenews:20******* *************** *****@mb-m16.aol.com...

I have an application that uses a LIstView.
Maybe 100 items each with 20 subitems.

The app looks at eack item and subitem twice.
I.e., it scans the entire set of data
item1, sub1,sub2,...
item2,sub1,sub2 ...
.
.
twice

I've never run it long enough for it to complete.
I'm using 3GHz CPU on an XPS by Dell

Could it be that accessing a ListView takes that long?

Thanks for any help

.

[Jerry Ham]

Yes - and over 2300 IP subnets and over 180 countries.
Major sites may have several DC's, minor sites have 1, and sites with less
than 100 users logon over the WAN.

Jerry

"CJ Taylor" <no****@blowgoa ts.com> wrote in message
news:vt******** ****@corp.super news.com...

You have 145 Domain Controllers???
"Jerry Ham" <No*****@Sompla ce.net> wrote in message
news:%2******** ********@tk2msf tngp13.phx.gbl. ..

Sounds like something in your code.

I've currently got a project with a listview for Active Directory Domain
controllers and properties (properties in the subitems). In our domain,
there are currently 145 DC, so 145 listview items, each with 5 subitems. I don't see any slowness there at all.

Jerry

"TryingLikeHeck " <tr************ @aol.com> wrote in message
news:20******** *************** ****@mb-m16.aol.com...

I have an application that uses a LIstView.
Maybe 100 items each with 20 subitems.

The app looks at eack item and subitem twice.
I.e., it scans the entire set of data
item1, sub1,sub2,...
item2,sub1,sub2 ...
.
.
twice

I've never run it long enough for it to complete.
I'm using 3GHz CPU on an XPS by Dell

Could it be that accessing a ListView takes that long?

Thanks for any help

[active]

Thanks for the replies. From them I get the understanding that ListViews are
not noted for being slow so I'll continue to look for better ways of doing
what I'm doing. The code is not short and I wouldn't expect anyone to spend
the time necessary to study it. I have already found a few places where I
can save some data instead of scanning more than once .

It also has a few redim perserve's that may slow things down.

Thanks again

"TryingLikeHeck " <tr************ @aol.com> wrote in message
news:20******** *************** ****@mb-m16.aol.com...

I have an application that uses a LIstView.
Maybe 100 items each with 20 subitems.

The app looks at eack item and subitem twice.
I.e., it scans the entire set of data
item1, sub1,sub2,...
item2,sub1,sub2 ...
.
.
twice

I've never run it long enough for it to complete.
I'm using 3GHz CPU on an XPS by Dell

Could it be that accessing a ListView takes that long?

Thanks for any help

[Cor]

Hi Active,

Slow is always subjective.

When you have a very wide Wan, you will have many thin parts in the pipeline
and the listview will probably not be the most important in that.

When you are on a computer that has direct access the full datatable all the
time without any data access problem, your listview will become earlier a
part of that pipeline to get the data.

I think a good comparer is explorer, that is a listview also and the user is
accepting it.

Therefore, in my eyes, when your program is much slower than explorer in
colleting data, you have a problem.

Although when you use things as redim I really think, that you have to check
what the arraylist of other fast ilist class can do for you.

Just a though

Cor