Thank you for answer.
The initial screen
and scrollbar move
That is GridViewComboBoxColumn.
Sorry i'm not good at english.
<telerikGridView:RadGridView x:Name="radGridView"
Grid.Row="2"
ItemsSource="{Binding UserCards}"
SelectedItem="{Binding SelectedUserCard, Mode=TwoWay}"
Margin="5"
SelectionMode="Single"
ShowGroupPanel="False"
AutoExpandGroups="True"
AutoGenerateColumns="False"
RowDetailsVisibilityMode="Collapsed"
RowIndicatorVisibility="Collapsed"
CanUserFreezeColumns="True"
FrozenColumnCount="2">
<telerikGridView:RadGridView.Columns>
<telerikGridView:GridViewComboBoxColumn
Header="{Binding ResourceWrapper.StringTable.AccessibleTimeGroup, Source={StaticResource StringTable}}"
DisplayMemberPath="Name"
CellStyleSelector="{StaticResource UserCardCellStyleSelector}"
DataMemberBinding="{Binding Card.AccessableTimeGroup}" ItemsSourceBinding="{Binding AccessibleTimeGroups}" />
</telerikGridView:RadGridView.Columns>
</telerikGridView:RadGridView>