Removing left and right border sides from listbox datatemplate - silverlight

Question

Currently I have specified borders for all datatemplated items in my horizontal listbox which is fine because I DO want borders for all individual listboxitems, but I would like to remove the left border from the first item and the right border from the last item. Is this even possible?
Xaml:
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical" Background="DimGray">
<Border BorderBrush="White" BorderThickness="1">
<Canvas Height="80" Width="140">
<TextBlock Text="{Binding Name}" TextAlignment="Center" Canvas.Top="22" Height="80" Width="140" FontSize="26"></TextBlock>
</Canvas>
</Border>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
Thanks

Answer 1

It is, with a DataTemplateSelector, you just need to implement the logic to select the correct DataTemplate, here's a fulle example with your code. You should be able to just copy / paste the following code in your project. There are comments in there that explain what's going on. Hope it helps!
XAML:
<Window x:Class="StackOverflowTests.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
xmlns:local="clr-namespace:StackOverflowTests"
Title="Window1"
x:Name="window1"
Width="800"
Height="600">
<Window.Resources>
<!-- Instantiate the DataTemplateSelector -->
<local:ItemDataTemplateSelector x:Key="ItemDataTemplateSelector" />
</Window.Resources>
<!-- Assign the DataTemplateSelector to the ListBox's ItemTemplateSelector -->
<ListBox Margin="8" ItemsSource="{Binding}" ItemTemplateSelector="{StaticResource ItemDataTemplateSelector}">
<ListBox.Resources>
<!-- Template without Left border -->
<DataTemplate x:Key="firstItemTemplate">
<StackPanel Orientation="Vertical" Background="DimGray">
<Border BorderBrush="Red" BorderThickness="0,1,1,1">
<Canvas Height="80" Width="140">
<TextBlock Text="{Binding Name}" TextAlignment="Center" Canvas.Top="22" Height="80" Width="140" FontSize="26"></TextBlock>
</Canvas>
</Border>
</StackPanel>
</DataTemplate>
<!-- Template with all borders -->
<DataTemplate x:Key="regularItemTemplate">
<StackPanel Orientation="Vertical" Background="DimGray">
<Border BorderBrush="Red" BorderThickness="1,1,1,1">
<Canvas Height="80" Width="140">
<TextBlock Text="{Binding Name}" TextAlignment="Center" Canvas.Top="22" Height="80" Width="140" FontSize="26"></TextBlock>
</Canvas>
</Border>
</StackPanel>
</DataTemplate>
<!-- Template without the Right border -->
<DataTemplate x:Key="lastItemTemplate">
<StackPanel Orientation="Vertical" Background="DimGray">
<Border BorderBrush="Red" BorderThickness="1,1,0,1">
<Canvas Height="80" Width="140">
<TextBlock Text="{Binding Name}" TextAlignment="Center" Canvas.Top="22" Height="80" Width="140" FontSize="26"></TextBlock>
</Canvas>
</Border>
</StackPanel>
</DataTemplate>
</ListBox.Resources>
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
</ListBox>
</Window>
C#:
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
namespace StackOverflowTests
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
this.DataContext = new List<Person>()
{
new Person() { Name = "Jim Morrison" },
new Person() { Name = "Ozzy Osbourne" },
new Person() { Name = "Slash" },
new Person() { Name = "Jimmy Page" }
};
}
}
public class Person
{
public string Name { get; set; }
}
public class ItemDataTemplateSelector : DataTemplateSelector
{
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
FrameworkElement element = container as FrameworkElement;
// get the ListBoxItem
ListBoxItem listBoxItem = element.TemplatedParent as ListBoxItem;
// get the ListBoxItem's owner ListBox
ListBox listBox = ItemsControl.ItemsControlFromItemContainer(listBoxItem) as ListBox;
// get the index of the item in the ListBox
int index = listBox.Items.IndexOf(item);
// based on the index select the template
if (index == 0)
return element.FindResource("firstItemTemplate") as DataTemplate;
else if (index == listBox.Items.Count - 1)
return element.FindResource("lastItemTemplate") as DataTemplate;
else
return element.FindResource("regularItemTemplate") as DataTemplate;
}
}
}