Question

Can someone tell me why the way I am binding data here does not work? I was able to do this fine with using a GridView. I am not sure why the data is not being passed to the user control here, in addition it compiles fine and shows the user controls with there default text

Main.xaml.cs:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Imaging;
using Windows.UI.Xaml.Navigation;

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238

namespace ItemsControlSample
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
    public MainPage()
    {
        this.InitializeComponent();
    }

    /// <summary>
    /// Invoked when this page is about to be displayed in a Frame.
    /// </summary>
    /// <param name="e">Event data that describes how this page was reached.  The Parameter
    /// property is typically used to configure the page.</param>
    protected override void OnNavigatedTo(NavigationEventArgs e)
    {
        PopulateData(); 

    }

    public class someKindaOfDataHolder
    {
        public string Text1;
        public string Text2; 
    }

    private void PopulateData()
    {
        List<someKindaOfDataHolder> dataAndStuff = new List<someKindaOfDataHolder>(); 

        for (int i = 0; i < 5; ++i)
        {
            dataAndStuff.Add(new someKindaOfDataHolder()
            {
                Text1 = "data spot 1: " + i.ToString(),
                Text2 = "data spot 2: " + (i + 2).ToString() 
            }); 

        }

        ListOfAUserControls.ItemsSource = dataAndStuff; 
    }


}
}

Main.xaml

<Page
x:Class="ItemsControlSample.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:ItemsControlSample"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
    <ScrollViewer>
            <ItemsControl x:Name="ListOfAUserControls" ItemsSource="{Binding}">
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                        <local:CustomUserControl DynamicText1Text="{Binding Text1}"  DynamicText2Text="{Binding Text2}" Margin="0,0,10,0"/> 
                    </DataTemplate>
            </ItemsControl.ItemTemplate>
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <StackPanel Orientation="Horizontal" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="100,46,-50,0"/>
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>

        </ItemsControl>
    </ScrollViewer>


</Grid>
</Page>

CustomUserControl.xaml.cs:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;

// The User Control item template is documented at http://go.microsoft.com/fwlink/?LinkId=234236

namespace ItemsControlSample
{
public sealed partial class CustomUserControl : UserControl
{


    public static readonly DependencyProperty DynamicText1Property =
     DependencyProperty.Register("DynamicText1Text", typeof(string), typeof(CustomUserControl), new PropertyMetadata(null, OnDynamicText1PropertyChanged));

    public string DynamicText1Text
    {
        get { return (string)GetValue(DynamicText1Property); }
        set { SetValue(DynamicText1Property, value); }
    }

    public static readonly DependencyProperty DynamicText2Property =
     DependencyProperty.Register("DynamicText2Text", typeof(string), typeof(CustomUserControl), new PropertyMetadata(null, OnDynamicText2PropertyChanged));

    public string DynamicText2Text
    {
        get { return (string)GetValue(DynamicText2Property); }
        set { SetValue(DynamicText2Property, value); }
    }

    public CustomUserControl()
    {
        this.InitializeComponent();
    }

    private static void OnDynamicText1PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var obj = d as CustomUserControl;
        obj.DynamicText1.Text = e.NewValue.ToString();
    }

    private static void OnDynamicText2PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var obj = d as CustomUserControl;
        obj.DynamicText2.Text = e.NewValue.ToString();
    }
}
}

CustomUserControl.xaml:

<UserControl
x:Class="ItemsControlSample.CustomUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:ItemsControlSample"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="800"
d:DesignWidth="800">

<Grid Background="Blue">
    <Grid.RowDefinitions>
        <RowDefinition Height="6*"/>
        <RowDefinition Height="2*"/>
    </Grid.RowDefinitions>

    <Image  Source="ms-appx:///Assets/MSIcon.png" />
    <StackPanel Grid.Row="1"   Margin="25">
        <TextBlock Text="Obay" FontSize="45" />
        <TextBlock x:Name="DynamicText1" Text="DynamicText1" FontSize="35" />
        <TextBlock x:Name="DynamicText2" Text="DynamicText2" FontSize="35" />
    </StackPanel>
</Grid>
</UserControl>

Thanks!

Answer 1

You need to set the DataContext somewhere. Without it – your bindings have no context and they fail (look at the Output window in VS when debugging Debug builds to see binding errors). You are setting ItemsSource=”{Binding}” where the binding has no context.

Then again – you are overriding the ItemsSource elsewhere with your “ListOfAUserControls.ItemsSource = dataAndStuff;” call, so that is likely not the issue causing your problem in the end. The DataContext of an item in an ItemsControl should be set automatically to an item in the ItemsSource collection.

Another problem that might block you there is that someKindaOfDataHolder.Text1 in your case is a field and it should be a property to work with bindings – try this instead:

public string Text1 { get; set; }