Question

Im having some problems with databinding inside a DataTemplate. In the ControlTemplate below the textbox in the Grid works and prints out the correct value. But the TextBlock inside the HyperlinkButtons DataTemplate does not work. Though the HyperlinkButtons NavigateUri is bound correctly. Could anyone plz help me with this

I have created a simple example that illustrates my problem.

MainPage.xaml

<UserControl x:Class="SilverlightApplication8.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:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <UserControl.Resources>
        <ControlTemplate x:Key="EventControlTemplate" TargetType="Button">
            <Grid>
                <!--WORKS-->
                <!--<Grid >
                    <TextBlock x:Name="TitleTextBlock" Text="{Binding Title}" Foreground="Red" FontWeight="Bold" />
                </Grid>-->

                <!--DOES NOT WORK-->
                <HyperlinkButton TargetName="_blank" NavigateUri="{Binding Url}"                                  >
                    <HyperlinkButton.ContentTemplate>
                        <DataTemplate>
                            <Grid>
                                <TextBlock Foreground="Green" Text="{Binding Title}"/>
                            </Grid>
                        </DataTemplate>
                    </HyperlinkButton.ContentTemplate>
                </HyperlinkButton>
            </Grid>
        </ControlTemplate>
    </UserControl.Resources>

    <Grid x:Name="LayoutRoot" Background="White">

        <ItemsControl x:Name="Links" Foreground="White" >
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <Border >
                        <Button Template="{StaticResource EventControlTemplate}" Click="Button_Click"/>
                    </Border>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>

    </Grid>
</UserControl>

MainPage.xaml.cs

using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;

namespace SilverlightApplication8
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();

            List<Events> events = new List<Events>();
            events.Add(new Events(){Title = "This is title 1", Url = "http://www.thesun.co.uk"});
            events.Add(new Events(){Title = "This is title 2", Url = "http://www.thesun.co.uk"});
            events.Add(new Events() { Title = "This is title 3", Url = "http://www.thesun.co.uk" });

            Links.ItemsSource = events;
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {

        }
    }

    public class Events
    {
        public string Url { get; set; }
        public string Title { get; set; }
    }
}

Answer 1

You’re setting the ContentTemplate, the DataContext of which will be the Content of the HyperlinkButton. Since you haven’t set the Content, you’re attempting to bind against null.

This should work:

<HyperlinkButton TargetName="_blank" NavigateUri="{Binding Url}" Content="{Binding Title}">
    <HyperlinkButton.ContentTemplate>
        <DataTemplate>
            <Grid>
                <TextBlock Foreground="Green" Text="{Binding .}"/>
            </Grid>
        </DataTemplate>
    </HyperlinkButton.ContentTemplate>
</HyperlinkButton>

But then that begs the question as to why you’re even setting the ContentTemplate instead of just doing this:

<HyperlinkButton TargetName="_blank" NavigateUri="{Binding Url}" Content="{Binding Title}"/>