Question

i have this DataTemplate:

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Model="clr-namespace:Effectus.Model"
xmlns:Controls="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit"
>

<DataTemplate DataType="{x:Type Model:ToDoAction}">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>

        <TextBlock Text="Title" 
                   Grid.Row="0" Grid.Column="0"/>
        <TextBox Text="{Binding Path=Title}"
                   IsEnabled="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}},Path=DataContext.AllowEditing.Value}"
                   Grid.Row="0" Grid.Column="1"/>

        <TextBlock Text="Content" 
                   Grid.Row="1" Grid.Column="0"/>
        <TextBox Text="{Binding Path=Content}"
            IsEnabled="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}},Path=DataContext.AllowEditing.Value}"
            AcceptsReturn="True"
            MinHeight="100"
            Grid.Row="2" Grid.ColumnSpan="2"/>

        <TextBlock Text="Owner"
                   Grid.Row="6" Grid.Column="0"/>
        <ComboBox SelectedItem="{Binding Path=Owner}" DisplayMemberPath="Username" SelectedValuePath="Username"
                  ItemsSource="{Binding Converter={StaticResource EnumValuesConverter}, ConverterParameter={x:Type Model:Status}}"
                  IsEnabled="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}},Path=DataContext.AllowEditing.Value}"
                  Grid.Row="6" Grid.Column="1"/>

    </Grid>
</DataTemplate>

In the last part you can see a TextBlock whose Text is “Owner”, followed by a ComboBox.
Just to give you the context, this is a little part of a ToDo app that i’m currently working on (i’m trying to get into MVVM).
The XAML i poted is the DataTemplate of the ToDoAction objects.
I want the “Owner” ComboBox to be filled by all users. I can get them from DB through NHibernate but i don’t have the faintest idea on how to bind the DataTemplate to my DataSource (a Nhibernate Session in my case, but i feel this is more general).
Can you give some little advise please?
Thank you all very much!

Answer 1

There are multiple ways to handle that like the ObjectDataProvider which i never used. But i think the most easiest and fastest is to use a singleton.

public sealed class UserList
{
    public ObservableCollection<User> Users {get; private set;}

    public static UserList Instance
    {
        get{return sInstance;}
    }

    private static UserList sInstance = new UserList();
}

you can update and modify the Users list as usual and the bindings to this collection must be.

ItemsSource="{Binding Source={x:Static my:UserList.Instance}, Path=Users}