<telerik:RadGridView Grid.Row="1" FontSize="12" IsFilteringAllowed="True" CanUserInsertRows="False" CanUserDeleteRows="False" AutoGenerateColumns="False" ShowGroupPanel="False" ItemsSource="{Binding ToListProducts}" IsReadOnly="True" SelectionMode="Extended" ShowColumnFooters="False" RowActivated="RadGridView_RowActivated" IsSynchronizedWithCurrentItem="True" Name="ToListGrid" dragDrop:RadDragAndDropManager.AllowDrag="True" AutoExpandGroups="True" SelectionChanged="ToListGrid_SelectionChanged">
<telerik:RadGridView.GroupDescriptors>
<telerik:GroupDescriptor Member="TypeName"
SortDirection="Ascending" />
</telerik:RadGridView.GroupDescriptors>
<telerik:RadGridView.Columns> .... </telerik:RadGridView.Columns></telerik:RadGridView>
ToListProducts is an ObservableCollection<>.
When loading data first time or refreshing data, I find one row is not displayed for each group region, but if I sort the data by clicking the column header, the missing row is showed out...
BTW, RadGridView of 2010.Q3 is much slower than 2010.Q2.SP2.
15 Answers, 1 is accepted
May you try your application with our Latest Internal Build and let me know the results ? In case the problem is not solved, I would need a bit more details about your specific settings - how do you load your data, what is its type ?
Considering your note about the performance of the RadGridView Q3 2010, it would be great if you could provide us with more information of the topic. When is the grid slower than before ? Are there any specific cases when you experience degraded performance ? We would be glad if you could share with us your feedback.
Maya
the Telerik team

I've not tested with the newest internal build.
But with the same code, after I switched back to 2010.Q2.SP2, the two problems disappeared. No rows are hidden, and the time cost to refresh data decreased dramatically.
The binded ObservableCollection contains entities from WCF RIA service...
Please open support ticket and send us an example where we can reproduce these problems.
All the best,Vlad
the Telerik team

For me this problem is very critical.
Has already opened a ticket?
Thanks.
Trilogis
ex.
<telerik:RadGridView Name="GridViewDevices" ItemsSource="{Binding Devices}" RowIndicatorVisibility="Collapsed" AutoExpandGroups="True" SelectionUnit="FullRow" IsReadOnly="True" AutoGenerateColumns="False" CanUserFreezeColumns="False" RowActivated="GridViewDevices_RowActivated" telerik:StyleManager.Theme="Windows7">
<telerik:RadGridView.GroupDescriptors>
<telerik:GroupDescriptor Member="DeviceType.Name" DisplayContent="Device Type" SortDirection="Ascending">
<telerik:GroupDescriptor.AggregateFunctions>
<telerik:CountFunction Caption="Devices:"/>
</telerik:GroupDescriptor.AggregateFunctions>
</telerik:GroupDescriptor>
</telerik:RadGridView.GroupDescriptors>
<telerik:RadGridView.Columns>
<telerik:GridViewDataColumn Header="Device Type" DataMemberBinding="{Binding DeviceType.Name}" />
<telerik:GridViewDataColumn Header="Code" DataMemberBinding="{Binding Code}" />
<telerik:GridViewDataColumn Header="MAC Address" DataMemberBinding="{Binding MacAddress}" />
<telerik:GridViewDataColumn Header="Name" DataMemberBinding="{Binding Name}" />
<telerik:GridViewDataColumn Header="Description" DataMemberBinding="{Binding Description}" />
</telerik:RadGridView.Columns>
</telerik:RadGridView>
I have used the code-snippet you provided for reproducing the issue but I was not able to. Please take a look at the sample project I used for testing it and feel free to change it in the way you necessitate. Let me know in case there are some discrepancies according to your requirements.
Maya
the Telerik team

I use GridView using various grouping, and in all cases, I have the same problem (see images attached).
If I group manually, it all work, but if i use the grouping by code, as shown below, the first line disappears!
I hope I was as clear as possible.
Thanks.
Trilogis.
I use MVVM pattern.
DeviceListModelView.cs
This property is filled with a WCF service.
public ObservableCollection<Device> Devices
{
get
{
if (null == _devices)
{
_devices = new ObservableCollection<Device>();
}
return _devices;
}
set
{
_devices = value;
RaisePropertyChanged("Devices");
}
}
Device.cs
public class Device
{
#region Private Declarations
private string _code;
private string _macAddress;
private DeviceType _deviceType;
#endregion
public string Code
{
get { return this._code; }
set { this._code = value; }
}
public string MacAddress
{
get { return this._macAddress; }
set { this._macAddress = value; }
}
/* Grouping property */
public DeviceType DeviceType
{
get { return this._deviceType; }
set { this._deviceType = value; }
}
}
XAML Navigation Page.
<navigation:Page.DataContext>
<viewmodel:DeviceListModelView></viewmodel:DeviceListModelView>
</navigation:Page.DataContext>
<telerik:RadBusyIndicator IsBusy="{Binding IsBusy}" IsIndeterminate="True" BusyContent="Caricamento dati in corso..." telerik:StyleManager.Theme="Windows7">
<Grid x:Name="LayoutRoot">
<Grid.RowDefinitions>
<RowDefinition Height="40"/>
<RowDefinition />
</Grid.RowDefinitions>
<Grid x:Name="GridBottom" Grid.Row="0">
<telerik:RadToolBar Name="radToolBar1" telerik:StyleManager.Theme="Windows7"/>
</Grid>
<Grid x:Name="GridTop" Grid.Row="1">
<telerik:RadGridView Name="GridViewDevices" ItemsSource="{Binding Devices}" RowIndicatorVisibility="Collapsed" AutoExpandGroups="True"
SelectionUnit="FullRow" IsReadOnly="True" AutoGenerateColumns="False" CanUserFreezeColumns="False"
RowActivated="GridViewDevices_RowActivated" telerik:StyleManager.Theme="Windows7">
<telerik:RadGridView.GroupDescriptors>
<telerik:GroupDescriptor Member="DeviceType.Name" DisplayContent="Tipologia dispositivo" SortDirection="Ascending">
<telerik:GroupDescriptor.AggregateFunctions>
<telerik:CountFunction Caption="Dispositivi:"/>
</telerik:GroupDescriptor.AggregateFunctions>
</telerik:GroupDescriptor>
</telerik:RadGridView.GroupDescriptors>
<telerik:RadGridView.Columns>
<telerik:GridViewDataColumn Header="Tipologia dispositivo" DataMemberBinding="{Binding DeviceType.Name}" />
<telerik:GridViewDataColumn Header="Codice dispositivo" DataMemberBinding="{Binding Code}" />
<telerik:GridViewDataColumn Header="MAC Address" DataMemberBinding="{Binding MacAddress}" />
<telerik:GridViewDataColumn Header="Nome" DataMemberBinding="{Binding Name}" />
<telerik:GridViewDataColumn Header="Descrizione" DataMemberBinding="{Binding Description}" />
</telerik:RadGridView.Columns>
</telerik:RadGridView>
</Grid>
</Grid>
</telerik:RadBusyIndicator>
I have tested the issue on a project using WCF Service. However, again I was not able to reproduce the problem. I am sending it to you so that you can test it too. Feel free to change it in the way you require and send it back. In case it is more appropriate for you, please send me your application so that I could see your exact settings and requirements.
On the other hand, did you try your project with the assemblies from our Latest Internal Build ?
Maya
the Telerik team

I thank you for the help that you're giving me.
In my case, it is impossible to send you my Enterprise Application.
I tried using, as you told me suggestion, Latest Internal Build assemblies.
I have not changed any settings, I just replaced the binaries folder with the new assembly...
(Rebuild Silverlight app) now, with this assemblies works all!
Greetings,
Manolo
Trilogis S.r.l.

I have a very similar problem too. I have a grid grouped by one of the columns in my data set. Once data is loaded, the name on the first (top) group in the grid is not displayed (as if it didn't have the name at all).
The list of groups is long, so you have to scroll to get to the bottom of it. When you scroll, random groups suddenly lose their names (happens to some of those groups that were not visible before scrolling). If you scroll back and forth, some names reappear, but other disappear.
I use WCF RIA to get my data to my grid. I build all grid colums and add GroupDescriptors in code.
Example of a column added to the grid:
...
gc = new GridViewDataColumn();
gc.Header =
"Title";
gc.DataMemberBinding =
new Binding("Title");
gc.CellStyle = (Style)Application.Current.Resources["ArrowStyle"]; gc.Width = WIDTH_TITLE;
gc.TextWrapping =
TextWrapping.Wrap;
rgvMainGrid.Columns.Add(gc);
Example of a GroupDescriptor added:
...
descriptor =
new GroupDescriptor();
descriptor.Member = "Title";
descriptor.SortDirection =
ListSortDirection.Ascending;
descriptor.DisplayContent =
"Title";
rgvMainGrid.GroupDescriptors.Add(descriptor);
...
Thank you!
-VK.
Hi trilogis,
Could you please download our latest release 2010 Q1 SP1 and the problem should disappear.
Greetings,
Milan
the Telerik team

If you mean Q1 2011 (the latest release you currently have), it does not fix the problem. At least not in my situation. The names of groups keep randomly disappearing on scrolling (happens in the areas that were not visible before scrolling, then became visible after scrolling). Multiple scrolling up and down makes some names appear again, but other names disappear. No action other than simple scrolling is taking place
-VK.
Hi trilogis,
I have attached our latest internal build which contains various fixes. Let me know if the problem is still there.
All the best,
Milan
the Telerik team

Milan,
I used the hotfix dlls, but still have the problem.
There is a thing I forgot to mention. The app is inside of an .aspx page, as usual. What's unusual is that the parent container that holds the app (<object ... id="objMyObject_Search"...) is getting resized (height is calculated and set for the <object></object> element with JavaScript code when onload or onresize are triggered (<body style="overflow: hidden" onload="BodySizeChanged()" onresize="BodySizeChanged();"...).
The javascript code:
function BodySizeChanged() {
var hght = 10;
if (document.body.scrollHeight) {
hght = document.body.scrollHeight;
}
else {
hght = document.documentElement.offsetHeight;
}
var elem = document.getElementById('objMyObject_Search');
elem.height = hght;
}
But I'm not sure if it is useful in figuring this problem out.
More details on the app.
When the problem occurs, the grid has about 30 collapsed groups. Each is supposed to have the name. If I make the browser window small enough for the scroll bar to appear, and then scroll, the newly revealed groups sometimes are missing their names. When i scroll back and forth, the nemaes reappear again, then disappear. i can't see a definite pattern in these disappearances as it seems to be happening on random.
The grid is in a UserControl that is instantiated inside of a RadPanelBar.
Thank you,
-VK.
Hi trilogis,
Seem that we need to further investigate this. Thanks for posting more info.
Regards,
Milan
the Telerik team
We have used the provided details but we were not able to reproduce the problem with missing names of the groups. You can find our test solution in the attached file. In case we have missed something that might be related to the problem, please feel free to modify the application and send it back to us. We will be glad to provide you with further assistance about the issue as soon as we succeed in reproducing it.
Greetings,
Yordanka
the Telerik team