We Keep Coding

WPF ListView Headers Repositioning

I have a ListView (with an inner ListView) that displays data like this:
I would like to display the inner ListView headers above the grouping like so:
Is it possible to re-position the column headers as shown or simply create some fake headers on the outer ListView?
Here is the XAML code I have so far:
<ListView Name="ListView_GarnishmentCalculations"
ItemsSource="{Binding GarnishedEmployees, UpdateSourceTrigger=PropertyChanged}"
MaxHeight="{Binding ActualHeight,
RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ScrollContentPresenter}},
Converter={StaticResource MathConverter}, ConverterParameter=x-220}"
Margin="5,20,10,10"
ScrollViewer.CanContentScroll="True"
ScrollViewer.VerticalScrollBarVisibility="Auto"
Grid.Row="2" Grid.Column="0" Grid.ColumnSpan="4">
<!-- Required for right justifying text in a TextBlock -->
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="HorizontalContentAlignment" Value="Stretch" />
</Style>
</ListView.ItemContainerStyle>
<!-- Group results and show EmpNo, Name and WorkState -->
<ListView.GroupStyle>
<GroupStyle>
<GroupStyle.HeaderTemplate>
<DataTemplate>
<Grid ShowGridLines="False">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="50" />
<ColumnDefinition Width="175" />
<ColumnDefinition Width="50" />
</Grid.ColumnDefinitions>
<TextBlock Text="{Binding Items[0].EmpNo}"
FontWeight="Bold"
Grid.Column="0" />
<TextBlock Text="{Binding Items[0].FullName}"
FontWeight="Bold"
Grid.Column="1" />
<TextBlock Text="{Binding Items[0].WorkState}"
FontWeight="Bold"
Grid.Column="2" />
</Grid>
</DataTemplate>
</GroupStyle.HeaderTemplate>
</GroupStyle>
</ListView.GroupStyle>
<ListView.ItemTemplate>
<DataTemplate>
<!-- Inner ListView of garnishment details -->
<ListView ItemsSource="{Binding Garnishments}">
<ListView.View>
<GridView>
<!-- CaseID -->
<GridViewColumn Width="100">
<GridViewColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding CaseNumber, Converter={StaticResource StringIsNullOrEmptyConverter}, ConverterParameter='No Case ID'}"
TextAlignment="Left">
</TextBlock>
</DataTemplate>
</GridViewColumn.CellTemplate>
<GridViewColumn.Header>
<GridViewColumnHeader Content=" Case ID" />
</GridViewColumn.Header>
</GridViewColumn>
<!-- Vendor -->
<GridViewColumn Width="150"
DisplayMemberBinding="{Binding Vendor}">
<GridViewColumn.Header>
<GridViewColumnHeader Content=" Vendor" />
</GridViewColumn.Header>
</GridViewColumn>
</GridView>
</ListView.View>
</ListView>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>

This is what I came up with, NOT by my self I used my google fu skills for this.
Credit to this SO post.
So here is what I have for my model:
namespace Model
{
public class Case
{
public int CaseID { get; set; }
public int Vendor { get; set; }
}
}
And now user:
namespace Model
{
public class User
{
public int ID { get; set; }
public string Name { get; set; }
public string State { get; set; }
public List<Case> Cases { get; set; }
}
}
Now in my MainViewModel:
using Model;
using System.Collections.Generic;
namespace VM
{
public class MainViewModel : BaseViewModel
{
public MainViewModel()
{
Users = new List<User>();
for (int i = 0; i < 20000; i++)
{
Users.Add(new User
{
ID = i,
Name = $"John the {i + 1}",
State = i % 2 == 0 ? "CA" : "IL",
Cases = new List<Case>() { new Case { CaseID = (i + 1) * 10, Vendor = ((i + 1) * 10) - 2 }, new Case { CaseID = (i + 1) * 10, Vendor = ((i + 1) * 10) - 2 } }
});
}
}
private List<User> users;
public List<User> Users
{
get { return users; }
set { users = value; OnPropertyChanged(); }
}
}
}
On to the View:
<Window x:Class="SO_App.MainWindow"
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"
xmlns:vm="clr-namespace:VM;assembly=VM"
xmlns:model="clr-namespace:Model;assembly=Model"
xmlns:local="clr-namespace:SO_App"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<vm:MainViewModel/>
</Window.DataContext>
<Window.Resources>
<CollectionViewSource Source="{Binding Users}" x:Key="Users"/>
</Window.Resources>
<Grid>
<ListView>
<ListView.ItemsSource>
<CompositeCollection>
<CollectionContainer Collection="{Binding Source={StaticResource Users}}"/>
</CompositeCollection>
</ListView.ItemsSource>
<ListView.View>
<GridView>
<GridViewColumn Header="Case ID" Width="100"/>
<GridViewColumn Header="Vendor" Width="100"/>
</GridView>
</ListView.View>
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListViewItem">
<ContentPresenter/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ListView.ItemContainerStyle>
<ListView.ItemTemplate>
<DataTemplate>
<DataTemplate.Resources>
<Style TargetType="TextBlock">
<Setter Property="FontWeight" Value="Bold"/>
</Style>
</DataTemplate.Resources>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<TextBlock Text="{Binding ID}" MinWidth="50"/>
<TextBlock Text="{Binding Name}" MinWidth="250" Grid.Column="1"/>
<TextBlock Text="{Binding State}" MinWidth="50" Grid.Column="2"/>
<ListView Grid.Row="1" ItemsSource="{Binding Cases}" Grid.ColumnSpan="3">
<ListView.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock Text="{Binding CaseID}" MinWidth="100"/>
<TextBlock Text="{Binding Vendor}" MinWidth="100" Grid.Column="1"/>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</Grid>
Caveat:
You will need to handle the scroll event on the inner ListView so it doesn't swallow the mouse scroll.
P.S.
this is the BaseViewModel implementation:
using System.ComponentModel;
using System.Runtime.CompilerServices;
namespace VM
{
public class BaseViewModel : INotifyPropertyChanged
{
#region INPC
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string prop = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(prop));
}
#endregion
}
}
Which then produces this as a result:

Cannot bind list of items in GridView column

I'm building an application that show to user the live result of a matches series. I setup the structure of data as follows: Countries->Leagues->Matches
In particular in the ViewModel I've created an observable collection of countries as follows:
private ObservableCollection<Models.Country> _countries = new ObservableCollection<Models.Country>();
public ObservableCollection<Models.Country> Country
{
get { return _countries; }
}
and the model:
public class Country
{
public string Name { get; set; }
public List<League> League { get; set; }
}
public class League
{
public string Name { get; set; }
public List<Event> Event { get; set; }
}
the class Event contains the properties of each event, in particular the name of the event, the date and so on..
I valorize this data as follows:
Country country = new Country();
country.Name = "Italy";
League league = new League();
league.Name = "Serie A";
League league2 = new League();
league2.Name = "Serie B";
Event #event = new Event();
#event.MatchHome = "Inter";
Event event2 = new Event();
#event.MatchHome = "Milan";
league.Event = new List<Event>();
league2.Event = new List<Event>();
league.Event.Add(#event);
league2.Event.Add(event2);
country.League = new List<League>();
country.League.Add(league);
country.League.Add(league2);
lsVm.Country.Add(country); //lsVm contains the ViewModel
How you can see I create an object called country (Italy) that will contains in this case two leagues (Serie A) and (Serie B). Each league contains one match actually in playing Serie A -> Inter and Serie B -> Milan
I add the league two the country, and finally the country to the observable collection in the viewmodel. Until here no problem. The problem's come in the xaml.
So I've organized all of this stuff inside of GroupViews, for doing this I'm using a CollectionViewSource, in particular:
<CollectionViewSource Source="{Binding Country}" x:Key="GroupedItems">
<CollectionViewSource.GroupDescriptions>
<PropertyGroupDescription PropertyName="Name" />
<PropertyGroupDescription PropertyName="League.Name" />
</CollectionViewSource.GroupDescriptions>
the code above is located in my Window.Resources, and tell to CollectionViewSource to organize for country name and leagues name the respective leagues associated.
I've two ListView as this:
<ListView ItemsSource="{Binding Source={StaticResource GroupedItems}}" Name="Playing">
<ListView.View>
<GridView>
<GridViewColumn Header="Date" Width="150" DisplayMemberBinding="{Binding Path = League.Event.MatchDate}"/>
<GridViewColumn Header="Minutes" Width="70" DisplayMemberBinding="{Binding Path = League.Event.MatchMinute}"/>
<GridViewColumn Header="Home" Width="150" DisplayMemberBinding="{Binding Path = League.Event.MatchHome}"/>
<GridViewColumn Header="Score" Width="100" DisplayMemberBinding="{Binding Path = League.Event.MatchScore}"/>
<GridViewColumn Header="Away" Width="150" DisplayMemberBinding="{Binding Path = League.Event.MatchAway}"/>
</GridView>
</ListView.View>
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<Expander IsExpanded="True" Background="#4F4F4F" >
<Expander.Header>
<StackPanel Orientation="Horizontal" Height="22">
<TextBlock Text="{Binding Name}" FontWeight="Bold" Foreground="White" FontSize="22" VerticalAlignment="Bottom" />
<TextBlock Text="{Binding ItemCount}" FontSize="22" Foreground="Orange" FontWeight="Bold" FontStyle="Italic" Margin="10,0,0,0" VerticalAlignment="Bottom" />
<TextBlock Text=" Leagues" FontSize="22" Foreground="White" FontStyle="Italic" VerticalAlignment="Bottom" />
</StackPanel>
</Expander.Header>
<ItemsPresenter />
</Expander>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
The GroupStyle contains the leagues that will contains each match, now the problem is that I can't see any league and any match 'cause this item are inside of a list. So for display them I should write in the xaml this code:
<PropertyGroupDescription PropertyName="League[0].Name" />
this fix the bug of the league name displayed into GroupStyle
and in the GridView:
<GridViewColumn Header="Casa" Width="150" DisplayMemberBinding="{Binding Path = League[0].Event[0].MatchHome}"/>
but this of course will display only the specific item.. not the list of items. I need help to fix this situation, I cannot figure out. Thanks.

If you want to use the ListView's grouping abilities, you have to provide it a flat list of the items you want to group (in your case, the leagues), not the header items. The CollectionView does the grouping for you by specifying GroupDescriptions.
For example, assuming the League class has a Country property:
class ViewModel
{
public ObservableCollection<Models.Country> Country { get; }
public IEnumerable<League> AllLeagues => Country.SelectMany(c => c.Leagues);
}
public class League
{
public string Name { get; set; }
public List<Event> Event { get; set; }
// add Country here
public Country Country { get; set; }
}
class
<CollectionViewSource Source="{Binding AllLeagues}" x:Key="GroupedItems">
<CollectionViewSource.GroupDescriptions>
<PropertyGroupDescription PropertyName="Country" />
</CollectionViewSource.GroupDescriptions>
Then when you bind the columns, you bind directly to League properties, e.g.:
<GridViewColumn Header="Date" DisplayMemberBinding="{Binding Path=Event.MatchDate}"/>
And in the group style you can bind to Country properties, as you've done.
Alternative solution
If you want to display any hierarchical data in WPF you can either use a control that was built for it (such as the Xceed data grid) or hack it together with the built-in WPF data grid's row details.
Here's a sample XAML for this (note it uses your original data structures without the modifications I suggested above). These are essentially 3 data grids nested within each other. Each grid has its own set of columns, so you can define anything you want for each level (Country, League, Event).
<Window x:Class="WpfApp.MainWindow"
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"
xmlns:app="clr-namespace:WpfApp"
d:DataContext="{d:DesignData ViewModel}">
<FrameworkElement.Resources>
<app:VisibilityToBooleanConverter x:Key="VisibilityToBooleanConverter" />
<DataTemplate x:Key="HeaderTemplate">
<Expander IsExpanded="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=DataGridRow}, Path=DetailsVisibility, Converter={StaticResource VisibilityToBooleanConverter}}" />
</DataTemplate>
<Style x:Key="DataGridStyle"
TargetType="DataGrid">
<Setter Property="RowHeaderTemplate"
Value="{StaticResource HeaderTemplate}" />
<Setter Property="RowDetailsVisibilityMode"
Value="Collapsed" />
<Setter Property="AutoGenerateColumns"
Value="False" />
<Setter Property="IsReadOnly"
Value="True" />
</Style>
</FrameworkElement.Resources>
<Grid>
<DataGrid ItemsSource="{Binding Country}"
Style="{StaticResource DataGridStyle}">
<DataGrid.Columns>
<DataGridTextColumn Header="Name"
Binding="{Binding Name}" />
</DataGrid.Columns>
<DataGrid.RowDetailsTemplate>
<DataTemplate>
<DataGrid ItemsSource="{Binding League}"
Style="{StaticResource DataGridStyle}">
<DataGrid.Columns>
<DataGridTextColumn Header="Name"
Binding="{Binding Name}" />
</DataGrid.Columns>
<DataGrid.RowDetailsTemplate>
<DataTemplate>
<DataGrid ItemsSource="{Binding Event}"
AutoGenerateColumns="False"
IsReadOnly="True">
<DataGrid.Columns>
<DataGridTextColumn Header="Match Home"
Binding="{Binding MatchHome}" />
</DataGrid.Columns>
</DataGrid>
</DataTemplate>
</DataGrid.RowDetailsTemplate>
</DataGrid>
</DataTemplate>
</DataGrid.RowDetailsTemplate>
</DataGrid>
</Grid>
</Window>
You'll also need the code for the converter I used:
public class VisibilityToBooleanConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
=> value as Visibility? == Visibility.Visible;
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
=> value as bool? == true ? Visibility.Visible : Visibility.Collapsed;
}

Add GroupDescription dynamically?

I'm looking for a way to add GroupDescriptions dynamically, in particular in the viewmodels, I actually add GroupDescription behind code like this:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
List<Country> items = new List<Country>();
items.Add(new Country() { Name = "Italy", League = new League { Name = "Serie A" } }); // Added "new League"
items.Add(new Country() { Name = "Italy", League = new League { Name = "Serie B" } });
items.Add(new Country() { Name = "England", League = new League { Name = "Premiere League" } });
items.Add(new Country() { Name = "Spain", League = new League { Name = "Primeira Division" } });
lvUsers.ItemsSource = items;
CollectionView view = (CollectionView)CollectionViewSource.GetDefaultView(lvUsers.ItemsSource);
PropertyGroupDescription groupNations = new PropertyGroupDescription("Name");
view.GroupDescriptions.Add(groupNations);
PropertyGroupDescription groupCompetions = new PropertyGroupDescription("League.Name"); // Changed "League" to "League.Name"
view.GroupDescriptions.Add(groupCompetions); // Fixed the variable name here
lvUsers.ItemsSource = view;
}
}
public struct League
{
public string Name { get; set; }
}
public struct Country
{
public string Name { get; set; }
public League League { get; set; } // added getter and setter
}
and this is my xaml:
<Window x:Class="GroupBox_Header.MainWindow"
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"
xmlns:local="clr-namespace:GroupBox_Header"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid Margin="10">
<ListView Name="lvUsers">
<ListView.View>
<GridView>
<GridViewColumn Header="Home Team" Width="50" DisplayMemberBinding="{Binding HomeTeam}" />
<GridViewColumn Header="Away Team" Width="50" DisplayMemberBinding="{Binding AwayTeam}" />
</GridView>
</ListView.View>
<ListView.GroupStyle>
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<Expander IsExpanded="True">
<Expander.Header>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Name}" FontWeight="Bold" Foreground="Gray" FontSize="22" VerticalAlignment="Bottom" />
<TextBlock Text="{Binding ItemCount}" FontSize="22" Foreground="Green" FontWeight="Bold" FontStyle="Italic" Margin="10,0,0,0" VerticalAlignment="Bottom" />
<TextBlock Text=" Items" FontSize="22" Foreground="Silver" FontStyle="Italic" VerticalAlignment="Bottom" />
</StackPanel>
</Expander.Header>
<ItemsPresenter />
</Expander>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
<GroupStyle>
<GroupStyle.ContainerStyle>
<Style TargetType="{x:Type GroupItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<Expander IsExpanded="True">
<Expander.Header>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding League}" FontWeight="Bold" Foreground="Gray" FontSize="22" VerticalAlignment="Bottom" />
</StackPanel>
</Expander.Header>
<ItemsPresenter />
</Expander>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</GroupStyle.ContainerStyle>
</GroupStyle>
</ListView.GroupStyle>
</ListView>
</Grid>
what I want to do is Bind in the ListView a collection that have the group description automatically.

If I understand your question right, you could either control the GroupDescriptions directly from the ViewModel, from code behind or create a custom ListView which let you bind to an ObservableCollection.
ViewModel
Use CollectionViewSource to get a hold of the CollectionView from the ViewModel. You could argue that this is an anti-pattern, but I think it is okay.
Code behind
Create a dependency property in you code behind that on change will update the group descriptors for the view. Then in you xaml bind that property to you ViewModel.
Custom ListView
Inherit from ListView and create a dependency property that let's you bind to an ObservableCollection.
Either way, you need to control different scenarios like, property
changed and collection changed.

Select text from a list view when that is cliked C# Metro App

I have a list view which I populate it from an API.. I want it fill a text box with the value which is found in the text block when I click..
My Listview...
<ListView Width="300" Height="134" x:Name="lsvObjectives" IsItemClickEnabled="True" SelectionMode="Multiple" ItemsSource="{Binding Source={StaticResource cvsObjectives}}" ItemClick="lsvObjectives_ItemClick">
<ListView.ItemsPanel>
<ItemsPanelTemplate>
<WrapGrid Orientation="Horizontal" HorizontalChildrenAlignment="left"/>
</ItemsPanelTemplate>
</ListView.ItemsPanel>
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="Padding" Value="0"/>
<Setter Property="Margin" Value="-7"/>
</Style>
</ListView.ItemContainerStyle>
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical" Margin="0,0,0,0" HorizontalAlignment="Center" >
<StackPanel Orientation="Horizontal" Width="310" Height="33" Background="#FFE9D5F0" HorizontalAlignment="Left">
<StackPanel Width="270" VerticalAlignment="Center" Margin="10,5,0,0">
<TextBlock Text="{Binding objective}" Style="{StaticResource ContentTextBlockStyle}" Foreground="Black" VerticalAlignment="Center" HorizontalAlignment="Left" FontSize="13"/>
</StackPanel>
</StackPanel>
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
This is how I populate the list:
private async void getObjectives()
{
string getObjectives = baseAddress + "unitPlansDetailsByUnit/1";
var content = await httpClient.GetStringAsync(new Uri(getObjectives));
objectivesHelper data = JsonConvert.DeserializeObject<objectivesHelper>(content);
foreach (var item in data.result)
{
cvsObjectives.Source = data.result;
}
}
My Classes:
public class objectives
{
public int id { get; set; }
public string objective { get; set; }
}
class objectivesHelper
{
public List<objectives> result { get; set; }
}
I am unable to read the value from the text block which is found in my list view..
Someone kindly help me do this..
Any kind of help is appreciated....

You can read the value in your lsvObjectives_ItemClick method by casting the ItemClickEventArgs.ClickedItem to your type objectives.
For example:
private void lsvObjectives_ItemClick(object sender, ItemClickEventArgs e)
{
objectives item = e.ClickedItem as objectives;
var itemText = item.objective;
youtTextBox.Text = item.Description.ToString();
}

How can the property of object in an inner ItemsControl bind to the property of an object in an outer ItemsControl?

The title might sound convoluted but bear with me.
I have Rooms which contain Occupants:
public class Room
{
public string Name { get; set; }
public List<Person> Occupants { get; set; }
public bool AreOccupantsEditable { get; set; }
}
public class Person
{
public string Name { get; set; }
}
Here's an array of Rooms:
<ResourceDictionary>
<x:Array x:Key="Rooms" Type="local:Room">
<local:Room Name="Happy Room" AreOccupantsEditable="True">
<local:Room.Occupants>
<local:Person Name="Mindy" />
</local:Room.Occupants>
</local:Room>
<local:Room Name="Sad Room" AreOccupantsEditable="True">
<local:Room.Occupants>
<local:Person Name="Bob" />
<local:Person Name="Jane" />
</local:Room.Occupants>
</local:Room>
<local:Room Name="Kill Room" AreOccupantsEditable="False">
<local:Room.Occupants>
<local:Person Name="Mork" />
<local:Person Name="Dave" />
<local:Person Name="Ryan" />
</local:Room.Occupants>
</local:Room>
</x:Array>
</ResourceDictionary>
Here is an ItemsControl in an ItemsControl, to display rooms and their occupants:
<ItemsControl ItemsSource="{Binding Source={StaticResource Rooms}}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel>
<!-- room name -->
<TextBlock Text="{Binding Path=Name}" />
<ItemsControl ItemsSource="{Binding Path=Occupants}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<!-- occupant name -->
<TextBox Text="{Binding Path=Name}" Margin="20,0,0,0" IsEnabled="{Binding ???}" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
Without Person having a reference to Room, how can I bind the IsEnabled property of the TextBox to the AreOccupantsEditable property of the Room a Person is in?
If it helps, here's an example project: http://dl.dropbox.com/u/4220513/ItemsControl-Binding.zip

You can use RelativeSource to access the outer DataContext :
IsEnabled="{Binding Path=DataContext.AreOccupantsEditable, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"

you can also use IsEnabled property of itemControl of Occupants to disable whole itemControl
<ItemsControl ItemsSource="{Binding Path=Occupants}" IsEnabled="{Binding Path=AreOccupantsEditable}">