How to bind a primitive type list to a DataGrid

Question

I need a DataGrid with just a single column of double type to be able to add, edit and delete entries from a local list variable.

My list is defined as an observable collection:

public ObservableCollection<double> Values = 
    new ObservableCollection<double>() { 1.0, 20 };

How to I bind the list to a DataGrid without wrapping it by a class?

Answer 1

If you don't want to create a data model with named properties (to use column auto generation) you will need to explicitly define the column layout by setting the DataGrid.DataGridTextColumn:

MainWindow.xaml

<Window>
  <Window.DataContext>
    <ViewModel />
  </Window.DataContext>

  <DataGrid ItemsSource="{Binding Values}" IsReadOnly="True" >  
    <DataGrid.Columns>
      <DataGridTextColumn Header="Value"
                          Binding="{Binding}" />
    </DataGrid.Columns>
  </DataGrid>
</Window>

ViewModel.cs

class ViewModel : INotifyPropertyChanged
{
  private ObservableCollection<double> values;
  public ObservableCollection<double> Values
  {
    get => this.values;
    set
    {
      this.values = value;
      OnPropertyChanged();
    }
  }

  // Constructor
  public void ViewModel()
  {
    // Initialize the data binding source of the DataGrid
    this.Values = new ObservableCollection<double>() { 1.0, 20 };
  }

  public event PropertyChangedEventHandler PropertyChanged;
  protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
  {
    this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
  }
}

Remarks
When binding the cell to the double values directly (or when using empty binding syntax in general e.g. {Binding} or {Binding Path=.}) BindingMode.TwoWay and therefore cell editing is not possible. This means BindingMode.TwoWay requires a property. Therefore to make cells editable the cell's binding source must expose the value via a property that is exposed by a wrapping type (data model or POCO).