<UserControl x:Class="ConditionalElementVisibility.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:ConditionalElementVisibility"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.Resources>
            <local:StringToVisibilityConverter x:Key="MyConverter" />
        </Grid.Resources>
        <telerik:RadGridView x:Name="RadGridView1" AutoGenerateColumns="False">
            <telerik:RadGridView.Columns>
                <telerik:GridViewDataColumn DataMemberBinding="{Binding ID}" >
                    <telerik:GridViewDataColumn.CellTemplate>
                        <DataTemplate>
                            <Grid>
                            <TextBlock Text="{Binding ID}" ToolTipService.ToolTip="{Binding Comment}"/>
                                <Border Background="Red" Visibility="{Binding Comment,Converter={StaticResource MyConverter}}" Width="5" Height="5"/>
                            </Grid>
                        </DataTemplate>
                    </telerik:GridViewDataColumn.CellTemplate>
                </telerik:GridViewDataColumn>
            </telerik:RadGridView.Columns>
        </telerik:RadGridView>
    </Grid>
</UserControl>
