Linq with Xceed's WPF Grid

Binding a read only Linq data table to Xceed's WPF data grid couldn't be easier, but things get a little trickier when you want insert/delete/update functionality.

The general recommendation (from Xceed's samples) is to implement a derived IBindingList collection class to provide the behaviour yourself.

Sounds like a lot of work to do something simple, especially if you want to bind to a lot of different objects - so here's a generic one I've prepared.

BTW: I haven't seen any articles on the web regarding best practice with this, so I'd love any comments if there is a better way.

  class LinqList<T> : BindingList<T>
  {
    ITable table = null;
    
    public LinqList(ITable table)
      : base(table.OfType<T>().ToList())
    {
      this.table = table;
    }
    
    protected override object AddNewCore()
    {
      T item = (T)base.AddNewCore();
    
      if (table != null)
        table.Add(item);
     
      return item;
    }
     
    public override void EndNew(int itemIndex)
    {
      base.EndNew(itemIndex);
    
      if (itemIndex >= 0)
        DataSource.Context.SubmitChanges();
    }
  
    protected override void RemoveItem(int index)
    {
      if (table != null)
        table.Remove(this[index]);
     
       base.RemoveItem(index);
    }
  }
   

My first code draft uses the BindingList as a base class (to avoid implementing everything myself) and takes a Linq data table as a constructor parameter.

Notice the OfType() call in the constructor, this provides basic support for inheritance with Linq, but more on that in a later post.

I use a singleton to store my Linq data context (DataSource.Context) to call SubmitChanges() after adding a new item.

  static class DataSource
  {
    static DataSource()
    {
      DataSource.Context = new MyDataContext();
    }

    static public MyDataContext Context { get; set; }
  }
  

Binding to Xceed

Simply bind an instance of this class to your data grid, and you're almost set!

See Part II for some changes that need to be made to the Xceed grid, to make this binding easier.