<telerik:DataGridTextColumn IsFrozen="True" HeaderText="BirthDay"
                                            DataMemberBinding="{Binding BirthDay}"
                                            ToolTipProperties.Text="{Binding BirthDay}" />

<telerik:DataGridTextColumn HeaderText="Country">
                    <telerik:DataGridTextColumn.DataMemberBinding>
                        <MultiBinding Converter="{StaticResource MultiConverter}">
                            <Binding Path="Country" />
                            <Binding Path="City" />
                        </MultiBinding>
 </telerik:DataGridTextColumn.

    private void TapGestureRecognizer_Tapped(object sender, TappedEventArgs e)
    {
        this.dataGrid.CommandService.ExecuteCommand(DataGridCommandId.CommitEdit, new EditContext(null, ActionTrigger.Programmatic, null));
    }

<Style TargetType="telerik:DataGridGroupingPanel">
    <Setter Property="BackgroundColor" Value="Red"/>
    <Setter Property="HeaderText" Value="Hello to group"/>
    <Setter Property="CornerRadius" Value="10"/>
    <Setter Property="BorderThickness" Value="2"/>
    <Setter Property="BorderColor" Value="Blue"/>
</Style>