Very bad performance in simple grid usage, scrolling and resizing

[Morten Nilsen]

Hello, I am having some serious issues here.

I have defined this grid:

<telerik:RadGridView
    x:Name="something"
    ItemsSource="{Binding Events}"
    telerik:Theming.Theme="Windows7"
    ShowGroupPanel="False"
    AutoGenerateColumns="False"
    ScrollMode="Deferred">
    <telerik:RadGridView.ScrollPositionIndicatorTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding ScrollIndicator}" />
        </DataTemplate>
    </telerik:RadGridView.ScrollPositionIndicatorTemplate>
    <telerik:RadGridView.Columns>
        <telerik:GridViewDataColumn Header="ID" DataMemberBinding="{Binding ID}" Width="100" />
        <!--<telerik:GridViewDataColumn Header="Artikkel" DataMemberBinding="{Binding Article}" />
        <telerik:GridViewDataColumn Header="Sats" DataMemberBinding="{Binding Batch}" />
        <telerik:GridViewDataColumn Header="Serienummer" DataMemberBinding="{Binding Serial}" />-->
        <telerik:GridViewDataColumn Header="Operasjon" DataMemberBinding="{Binding EventType}" Width="150" />
        <telerik:GridViewDataColumn Header="Startet" DataMemberBinding="{Binding Started}" Width="100" />
        <telerik:GridViewDataColumn Header="Avsluttet" DataMemberBinding="{Binding Ended}" Width="100" />
        <telerik:GridViewDataColumn Header="Status" Width="100">
            <telerik:GridViewDataColumn.CellTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Status}" HorizontalAlignment="Left" FontWeight="Bold" Foreground="{Binding StatusColor}" />
                </DataTemplate>
            </telerik:GridViewDataColumn.CellTemplate>
        </telerik:GridViewDataColumn>
        <telerik:GridViewDataColumn Header="Bruker" DataMemberBinding="{Binding EmployeeID}" Width="100" />
        <telerik:GridViewDataColumn Header="Informasjon" DataMemberBinding="{Binding Information}" Width="300" />
    </telerik:RadGridView.Columns>
</telerik:RadGridView>

Using a bog standard ListView, this was performing just fine - but now I am having UI hangs while scrolling (when scrollmode was realtime) and I get a black background inside the window border while resizing..

What am I missing?

  // Regards, Morten

[Maya]

Hello Morten Nilsen,

I have tried to reproduce the issue you reported, but unfortunately without any success. Could you take a look at the sample attached and let me know whether you can get the same behavior on it ? Is there something that I am missing ?  

Best wishes,
Maya
the Telerik team

[Morten Nilsen]

Hello, thanks for taking the time to look at it.

I am seeing the exact same behaviour with your sample as my own code.
Clicking the tray to scroll, there is a noticable delay before the grid scrolls, and resizing the window, I see a black background inside the window.

// Regards, Morten

[Morten Nilsen]

I changed the ScrollMode to RealTime, and rapidly scrolled to the top and bottom several times.
Just like I was experiencing on my own codebase, the drag handle was lagging behind the mouse.

  // Regards, Morten

[Morten Nilsen]

Breakthrough!
When I disable virtualization on your sample application, the performance problem goes away!
But I would expect that to be a bad idea for grids with many rows.

  // Cheers, Morten

[Morten Nilsen]

Yeah, going back to my application, horizontal scrolling becomes unusable and the application hangs a bit when loading the grid.
I wouldn't say I have a lot of rows, though - it is less than 200..

  // Regards, Morten

[Maya]

Hello,

I have made yet another try on the sample I previously attached, but unfortunately I am still not able to reproduce the behavior you described. Could you take a look at this small video illustrating my attempts ? Am I missing something ? Is there anything more that I need to do in order to get the same behavior ? 
Nevertheless, it is not recommended to turn off the virtualization as the performance of the grid will most probably be degraded.
 

Greetings,
Maya
the Telerik team

[Morten Nilsen]

Hello,

I definitely do not want to turn off virtualization, I merely did so as a step in my testing :)
For the interim, I opted to use the standard WPF grid.

In your video, you can spot one of the things I described, the black flash towards the end after you enable real-time scrolling.

I just now started up my own application without VS attached, and it does appear to be dramatically more well behaved..
Before doing that, I turned on "Just My Code" and set Data Binding under WPF Trace settings to off for the output window, without that affecting the performance.

What sort of a computer are you testing these things on?
This box is a Core2 Duo E8500 with 8GB RAM and 64 bit Windows 7.

  // Regards, Morten

[Morten Nilsen]

I found the cause!

My IntelliTrace was set to trace events and call information.
When I changed it to events only, the performance problem vanished immediately!

  -- Cheers, Morten