Why isn't my WPF Datagrid showing data?

Question

This walkthrough says you can create a WPF datagrid in one line but doesn\'t give a full example.

So I created an example using a generic list and connected it to th

Answer 1

Typically in WPF, you would leverage an ObservableCollection<>

Because then you can just .Add() / .Remove() elements to/from the source collection, and any controls bound (Data Binding) automatically get updated (Automatic Property Change Notification). Those are 2 important concepts in WPF.

Main Window View Model

using System.Collections.Generic;

namespace TestDatagrid345.ViewModels
{
  class Window1ViewModel
  {
    private ObservableCollection _customers = new ObservableCollection();
    public ObservableCollection Customers
    {
      Get { return _customers; }
    }
  }
}

Main Window

using System.Collections.Generic;
using System.Windows;

namespace TestDatagrid345
{
  public partial class Window1 : Window
  {
    Window1ViewModel _viewModel;

    public Window1()
    {
      InitializeComponent();
      _viewModel = (Window1ViewModel)this.DataContext; // @#$% (see XAML)
    }

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
      // but this stuff could instead be done on a 'Submit' button click on form:
      _viewModel.Customers.Add(new Customer { FirstName = "Tom", LastName = "Jones" });
      _viewModel.Customers.Add(new Customer { FirstName = "Joe", LastName = "Thompson" });
      _viewModel.Customers.Add(new Customer { FirstName = "Jill", LastName = "Smith" });
    }
  }
}

Main Window XAML