Question

I’m trying to bind my view to my view model without DataObjectProvider.

The following code runs without an error, but my ListBox is empty.

As far as I can tell, I correctly:

• set the View’s DataContext to the ViewModel itself (DataContext = new CustomersViewModel();)
• expose the customer objects in the ViewModel (public static ObservableCollection<Customer> GetAll())
• bind the ListBox to the customer objects (ItemsSource="{Binding GetAll}")

What little piece of syntax am I missing here?

CustomersView.xaml:

<UserControl x:Class="TestDynamicForm123.View.CustomersView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <UserControl.Resources>
        <Style x:Key="allCustomersListBox" TargetType="ListBox">
            <Setter Property="BorderThickness" Value="0"/>
        </Style>
        <DataTemplate x:Key="allCustomersDataTemplate">
            <StackPanel Orientation="Horizontal">
                <TextBlock Text="{Binding FirstName}"/>
                <TextBlock Text=" "/>
                <TextBlock Text="{Binding LastName}"/>
            </StackPanel>
        </DataTemplate>
    </UserControl.Resources>

    <StackPanel Style="{StaticResource viewWrappingStackPanel}">
        <ListBox ItemsSource="{Binding GetAll}"
                 ItemTemplate="{StaticResource allCustomersDataTemplate}"
                 Style="{StaticResource allCustomersListBox}">
        </ListBox>
    </StackPanel>
</UserControl>

CustomersView.xaml.cs:

using System.Windows.Controls;
using TestDynamicForm123.ViewModel;

namespace TestDynamicForm123.View
{
    public partial class CustomersView : UserControl
    {
        public CustomersView()
        {
            InitializeComponent();

            DataContext = new CustomersViewModel();
        }
    }
}

CustomersViewModel.cs:

using System.Collections.ObjectModel;

namespace TestDynamicForm123.ViewModel
{
    public class CustomersViewModel
    {
        public static ObservableCollection<Customer> GetAll()
        {
            return Customer.GetAll();
        }
    }
}

Customer.cs: (model)

using System.Collections.ObjectModel;

namespace TestDynamicForm123.ViewModel
{
    public class Customer
    {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public int Age { get; set; }

        public static ObservableCollection<Customer> GetAll()
        {
            ObservableCollection<Customer> customers = new ObservableCollection<Customer>();
            customers.Add(new Customer() { FirstName = "Jay", LastName = "Anders", Age = 34 });
            customers.Add(new Customer() { FirstName = "Jim", LastName = "Smith", Age = 23 });
            customers.Add(new Customer() { FirstName = "John", LastName = "Jones", Age = 22 });
            customers.Add(new Customer() { FirstName = "Sue", LastName = "Anders", Age = 21 });
            customers.Add(new Customer() { FirstName = "Chet", LastName = "Rogers", Age = 35 });
            customers.Add(new Customer() { FirstName = "James", LastName = "Anders", Age = 37 });
            return customers;
        }

    }
}

Answer 1

The problem is that you are trying to bind to CustomerViewModel.GetAll(), when GetAll in CustomerViewModel is a static function not an instance property.

Change the static function to something like this (in CustomerViewModel):

public ObservableCollection<Customer> GetAll
{
    get { return Customer.GetAll(); }
}