Binding to a dependency property of a user control WPF/XAML

Question

My app looks like this:

---

SectionHeader

SectionHeader

Content

SectionHeader

Conte

Answer 1

Give a name to your usecontrol and try binding like this

ItemsSource="{Binding Apps,ElementName=root}"

and root is the name give to your usercontrol

  <UserControl x:Class="WpfApplication1.MainWindow"
            xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             Height="350" Width="525"
     x:Name="root">

it is element binding to user control which has Apps property

Answer 2

Have you tried

Apps="{Binding Apps}" 

instead of

Apps="{Binding Path=Apps}"

in your top level control?

Also, do you get any binding errors in the VS output window when you run the app?

Answer 3

Having tried to repro this from your description and coming across a similar problem I found that the only way I could make it work is to not set the DataContext of the UserControl, and instead use ElementBinding:

<UserControl x:Class="WpfApplication2.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             x:Name="thisUC"
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <Border Background="Red" Padding="10">
        <ListBox x:Name="ucList" ItemsSource="{Binding ElementName=thisUC, Path=UCApps}"/>
        </Border>

    </Grid>
</UserControl>

The implementation of this UC is trivially simple:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Collections.ObjectModel;
using System.Collections;

namespace WpfApplication2
{
    /// <summary>
    /// Interaction logic for UserControl1.xaml
    /// </summary>
    public partial class UserControl1 : UserControl
    {
        public IEnumerable UCApps
        {
            get { return (IEnumerable)GetValue(UCAppsProperty); }
            set { SetValue(UCAppsProperty, value); }
        }

        // Using a DependencyProperty as the backing store for Apps.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty UCAppsProperty =
            DependencyProperty.Register("UCApps", typeof(IEnumerable), typeof(UserControl1), new UIPropertyMetadata(null));

        public UserControl1()
        {
            InitializeComponent();            
        }
    }
}

as is the XAML that calls it:

<Grid >
    <my:UserControl1 x:Name="ucName" UCApps="{Binding Path=Apps}"/>
</Grid>

(I changed the name of Apps in your Usercontrol to UCApps so I could see what was going on - too many properties with the same name got confusing!)

Answer 4

Apps="{Binding Path=Apps}"

Binds Apps to itself.

Try following

1) Your ViewModel should be a DataContext of Control, then you can use following

Apps="{Binding DataContext.Apps}"

Also you can use Snoop utility to find binding issues in real time