Correct method of casting to a strongly typed dataset

Question

I have a WPF treeview that is loaded from a set of classes hierarchy (strongly-typed-dataset (Entity Framework).) I am looking for the correct way to cast these nodes back as one of these objects.

At the moment I have to write code for each class within my hierarchy (This is an example of how I am deleting an object):

            if (MainTree.SelectedItem is tblProject)
            {
                var s = (tblProject)MainTree.SelectedItem;
               _context.tblProjects.Remove(s);
            }

            if (MainTree.SelectedItem is tblLine)
            {
                var s = (tblLine)MainTree.SelectedItem;
                _context.tblLines.Remove(s);
            }

            if (MainTree.SelectedItem is tblDevice)
            {
                var s = (tblDevice)MainTree.SelectedItem;
                _context.tblDevices.Remove(s);
            }

I would like to know how I could reduce this code, and make it more flexible, so that I do not have to add code for each class that I might add in the future.

Answer 1

In case of EF you can use _context.Set(MainTree.SelectedItem.GetType()).Remove(MainTree.SelectedItem)

In general I would recomend to take a look into Data Binding and MVVM patttern to avoid the similar situations