将DataGrid绑定到ModelWrapper的ObservableCollection <Model>

Question

Auto-Generating Columns for the Properties of a Wrapped-Object

I am wanting to have AutoGeneratedColumns="true" but my I'm not sure how to do this with this ModelWrapper design. (I'm following the early stages of PluralSight.com's "Advanced Model Treatment" course).

My <datagrid> in a working state (This has manually defined columns, but I want autogenerated columns - while persisting with this ModelWrapper pattern):

<DataGrid Grid.Row="0"
          Grid.RowSpan="2"
          Grid.Column="1"
          DockPanel.Dock="Top"
          ItemsSource="{Binding Segments}"
          SelectionUnit="FullRow" 
          AutoGenerateColumns="False">      

         <DataGrid.Columns>
             <DataGridTextColumn Header="Name" Width="1*" Binding="{Binding Model.Name}"/>
             <DataGridTextColumn Header="Notes" Width="2*" Binding="{Binding Model.Notes}"/>
        </DataGrid.Columns>

</DataGrid>

Note: that the DataContext for the <datagrid> above (ie the associated ViewModel) exposes an ObservableCollection<ModelWrapper<Segment>> called Segments .

Here is my ModelWrapper class that is used to wrap a basic class with only CLR properties (I hazard a guess the problem is not here - or in my model definition further below):

Note: Observable implements INotifyPropertyChanged .

internal class ModelWrapper<T> : Observable
{
    public ModelWrapper(T model)
    {
        if (model == null)
            throw new ArgumentNullException(nameof(model));
        Model = model;
    }

    public T Model { get; }

    protected void SetValue<TValue>(TValue value, [CallerMemberName] string propertyName = null)
    {
        var propertyInfo = Model.GetType().GetProperty(propertyName);
        var currentValue = propertyInfo.GetValue(Model);
        if (Equals(currentValue, value)) return;
        propertyInfo.SetValue(Model, currentValue);
        OnPropertyChanged(propertyName);
    }

    protected TValue GetValue<TValue>([CallerMemberName] string propertyName = null)
    {
        var propertyInfo = Model.GetType().GetProperty(propertyName);
        return (TValue) propertyInfo.GetValue(Model);
    }
}

Here is the model class that is wrapped by the ModelWrapper:

internal class Segment
{
    public string Notes { get; set; }
    public string Name  { get; set; }
}

If I set AutoGenerateColumns to True , then I only get one column with the Header ...Model (ie ToString() -ing the Model object).

I've rushed ahead of the course and am trying to implement something with the ModelWrapper pattern. Can I autogenerate the columns, as per the properties of the ordinaryCLRobject?

How? What and I doing wrong? ... thanks in advance. :-)

Answer 1

My problem was that I was creating ObservableCollections of type ModelWrapper instead of, in my case, SegmentWrapper : ModelWrapper<Segment> .

I can then remove Model. from the binding path in my xaml columns, ie:

        <DataGrid.Columns>
             <DataGridTextColumn Header="Name" Width="1*" Binding="{Binding Name}"/>
             <DataGridTextColumn Header="Notes" Width="2*" Binding="{Binding Notes}"/>
        </DataGrid.Columns>