Binding a wpf listbox to a combobox

I have created a very basic wpf application that I want to use to record time entries against different projects. I havent used mvvm for this as I think its an overkill.

I have a form that contains a combobox and a listbox. I have created a basic entity model like this

What I am trying to do is bind the combobox to Project and whenever I select an item from the combobox it updates the listview with the available tasks associated with that project.

This is my xaml so far. I dont have any code behind as I have simply clicked on that Data menu and then datasources and dragged and dropped the items over. The application loads ok and the combobox is been populated however nothing is displaying in the listbox.

Can anyone tell me what I have missed?

    <Window.Resources>
    <CollectionViewSource x:Key="tasksViewSource" d:DesignSource="{d:DesignInstance l:Task, CreateList=True}" />
    <CollectionViewSource x:Key="projectsViewSource" d:DesignSource="{d:DesignInstance l:Project, CreateList=True}" />
</Window.Resources>
<Grid DataContext="{StaticResource tasksViewSource}">
    <l:NotificationAreaIcon 
                  Text="Time Management" 
                  Icon="Resources\NotificationAreaIcon.ico"
                  MouseDoubleClick="OnNotificationAreaIconDoubleClick">
        <l:NotificationAreaIcon.MenuItems>
            <forms:MenuItem Text="Open" Click="OnMenuItemOpenClick" DefaultItem="True" />
            <forms:MenuItem Text="-" />
            <forms:MenuItem Text="Exit" Click="OnMenuItemExitClick" />
        </l:NotificationAreaIcon.MenuItems>
    </l:NotificationAreaIcon>
    <Button Content="Insert" Height="23" HorizontalAlignment="Left" Margin="150,223,0,0" Name="btnInsert" VerticalAlignment="Top" Width="46" Click="btnInsert_Click" />
    <ComboBox Height="23" HorizontalAlignment="Left" Margin="70,16,0,0" Name="comProjects" VerticalAlignment="Top" Width="177" DisplayMemberPath="Project1" ItemsSource="{Binding Source={StaticResource projectsViewSource}}" SelectedValuePath="ProjectID" />
    <Label Content="Projects" Height="28" HorizontalAlignment="Left" Margin="12,12,0,0" Name="label1" VerticalAlignment="Top" IsEnabled="False" />
    <Label Content="Tasks" Height="28" HorizontalAlignment="Left" Margin="16,61,0,0" Name="label2" VerticalAlignment="Top" />
    <ListBox Height="112" HorizontalAlignment="Left" Margin="16,87,0,0" Name="lstTasks" VerticalAlignment="Top" Width="231" DisplayMemberPath="Task1" ItemsSource="{Binding Path=ProjectID, Source=comProjects}" SelectedValuePath="TaskID" />
    <TextBox Height="23" HorizontalAlignment="Left" Margin="101,224,0,0" Name="txtMinutes" VerticalAlignment="Top" Width="42" />
    <Label Content="Mins to Insert" Height="28" Horizon开发者_StackOverflowtalAlignment="Left" Margin="12,224,0,0" Name="label3" VerticalAlignment="Top" />
    <Button Content="None" Height="23" HorizontalAlignment="Left" Margin="203,223,0,0" Name="btnNone" VerticalAlignment="Top" Width="44" />
</Grid>

You set the DataContext in the Grid, so just change your ItemsSource as indicated below.

<Grid DataContext="{StaticResource tasksViewSource}"> 
  <ListBox Height="112"  
           HorizontalAlignment="Left"  
           Margin="16,87,0,0"  
           Name="lstTasks"  
           VerticalAlignment="Top"  
           Width="231"  
           DisplayMemberPath="Task1"  
           ItemsSource="{Binding}"  
           SelectedValuePath="TaskID" />  
 </Grid>

You'll also want to filter the task list, to do that just change the generated code. Here is an example I hacked together. You can toggle the value using the SelectionChanged event from your ComboBox.

private System.Data.Objects.ObjectQuery<Models.Task> GetTasksQuery(Models.StackoverflowEntities stackoverflowEntities)
{
  // get the selected item
  int id = (int)cboProjects.SelectedValue;
  System.Data.Objects.ObjectQuery<CollectionViewSourceEF.Models.Task> tasksQuery = stackoverflowEntities.Tasks.Where(task => task.ProjectID == id) as ObjectQuery<Task>;
  return tasksQuery;
}