VB.NET Custom Object Master-Detail Data Binding

Question

Since beginning to use VB.NET some years ago I have become slowly familiar with using the data binding features of .NET, however I often find my self bewildered by it's behavior and instead of discover the correct way it should work I find some dirty work around to suit my needs and continue on.

Needless to say my problems continue to arise.

I am using Custom Objects as the Data Sources for by controls and often entire forms. I find it frustrating to separate business logic and the graphical interface. (That could be a new question entirely.) So for a lot of objects I generate a form which has the DataBindingSource for the object. When I create each from using the New Constructor I explicitly pass to it the object to which it should be bound, and then set this passed object as the DataSource of the BindingSource. (That's a mouthful!)

Now the Master object (say, bound to each form) often contains a List of objects which I like to have displayed in a DataGridView. I (sometimes) create and modify these child objects in their own form (again creating a databind the same way as the master form) but when I add them to the List in the master object the DataGridView won't update with the new items.

So my question really has a few layers:

1. How can I easily/efficiently/correctly update this DataGridView with the list of Detail objects when I add them to the list of the Master object.

2. Is this approach to DataBinding good/viable.

3. What's the best way to separate business logic from graphical interface.

Answer 1

1) use BindingList<T>. it handles all of the refreshing of the gridview for you. i've used this many times, and i love it. it's super easy and does what you want. http://msdn.microsoft.com/en-us/library/ms132679.aspx

2) yes

3) Model-View-Presenter pattern with a ViewModel or PresentationModel. there's a lot of great info on Model-View-Presenter out there on the web. read up on it and learn it well. and by the way: you'll see a lot of MVP info related to web development with asp.net webforms... it works just as well in WinForms development. I've been using MVP in winforms for years.