Since this is WPF, it may look like lots of code, but don't be frightened, the question is really simple!
I have the following XAML:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:hax="clr-namespace:hax" x:Class="hax.MainWindow"
x:Name="Window" Title="Haxalot" Width="640" Height="280">
<Grid x:Name="LayoutRoot">
<ListView ItemsSource="{Binding AllRoles}" Name="Hello">
<ListView.View>
<GridView>
<GridViewColumn Header="Name"
DisplayMemberBinding="{Binding Path=FullName}"/>
<GridViewColumn Header="Role"
DisplayMemberBinding="{Binding Path=RoleDescription}"/>
</GridView>
</ListView.View>
</ListView>
</Grid>
</Window>
I have this code-behind:
using System.Collections.ObjectModel;
using System.Windows;
namespace hax
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public ObservableCollection<Role> AllRoles { get { return m_AllRoles; } set { m_AllRoles = value; } }
private ObservableCollection<Role> m_AllRoles = new ObservableCollection<Role>();
public MainWindow()
{
this.InitializeComponent();
AllRoles.Add(new Role("John", "Manager"));
AllRoles.Add(new Role("Anne", "Trainee"));
// Hello.ItemsSource = AllRoles; // NOTE THIS ONE!
}
}
}
If I leave the statement Hello.ItemSource = AllRoles
commented out, the grid displays nothing. When I put it back in, it displays the correct thing. Why is this?
This:
means "Bind
ItemsSource
to the propertythis.DataContext.AllRoles
" wherethis
is the current element.means "Bind
ItemsSource
to anObservableCollection<T>
full of roles", which directly does what you were trying to do originally.There are a number of ways to do this in xaml. Here's one:
and in the xaml
OR, alternatively, you could make AllRoles a public property of the window
and then use a RelativeSource to tell the Binding to walk up the logical tree to the Window
Which means "Look at my ancestry until you find a Window, then look for a public property on the window called AllRoles".
But the best way to do this is to skip the frigging codebehind altogether and use the MVVM pattern. I'd suggest if you're learning that you skip directly to the MVVM pattern. The learning curve is steep, but you learn all about binding and commands and the important, cool things about WPF.
When you bind to a datasource in WPF, it is looking for a property of your Window's data context called "AllRoles". Check out the Model-View-ViewModel pattern for more on data binding in xaml. http://msdn.microsoft.com/en-us/magazine/dd419663.aspx