Before continue our tutorial I want to take a break and talk about the messaging options. Also because the MVVM is a new interpretation of an old pattern, some of my friends are using the Mediator Pattern and today we must talk about that before building the Details view. As it was requested by many people, here is the location of the source code on CodePlex: www.codeplex.com/MVVM. Please refer there to any issue. Communication through the views. Before starting we need to spend 5 minutes over the communication. The first solution we used...

Ok, starting from this post we are going to do something really interesting. In this episode we need to create a simple List windows, but as you will see the logic will not be so different then a one-to-many form. This will be the final result: The ViewModel for the List Window. First of all we need to create the view model. The view model should have the following commands: New – Add a new Customer Save – Save all the changes we did … ...

Today we are going to create the start-up form of our project and use the first ViewModel to run the application logic. The result we want to obtain will be: The View Model for the Startup form. In our project, let’s go to the ViewModel section and create a new class. This class will inherit from the basic View Model class like the code below: 1: public class StartViewModel : ViewModel { 2: 3: public StartViewModel() { 4: 5: ...

As we saw in the previous posts, a view model should be an abstract implementation of what the view needs to show about the model. We should implement an observable collection of something, we should implement an INotifyPropertyChanged interface and we should have a collection of RelayCommands. For these reasons, it simply to understand that we need a basic abstract ViewModel class, just to recycle some code. The Basic View Model. 1: namespace MVVM.ViewModel { 2: public abstract class ViewModel:INotifyPropertyChanged,IDisposable { 3: 4: ...

In the previous posts we saw the basic of our project, the model (domain entities) and a simple repository. Note: please note that the sample I wrote about an agnostic UnitOfWork is just to show you a simple pattern to handle L2S but it can be done better. The ViewModel. What is the view model? Well the simplest explanation is enclosed in this definition: the view model should be the datacontext of our view. It should provide the commands, the observable collections used in the view and the error logic. Before starting to view how to...

Before starting to view in depth our model, or to design the views, I want to complete the DAL layer. Now that we have our unit of work implementation and our data context we need to implement a couple of repositories. If you want to view how it should work a repository, I suggest this interesting article from Martin Fowler. The presenter should be: A Repository mediates between the domain and data mapping layers, acting like an in-memory domain object collection. The Flow of our application. During the time I saw different...

In the first part of this tutorial we saw the MVVM model and how it works. In this part of our tutorial we will work directly with the Entity Model and LinqToSQL. I am using a database-first approach so in my opinion using LinqToSQL will be better then Entitiy Framework. I am going also to show you an easy way to build a custom Unit Of Work to manage the context status with Linq 2 SQL. The Visual Studio Project. First of all open a blank Visual Studio solution, I called it WPF.Tutorial.VMMV. Add two projects on...

With Microsoft WPF technology, a new pattern is born and is going to be called MVVM (Model View ViewModel). This pattern is an hybrid from the old MVC and the old MVP patterns. Why a new pattern for the presentation? First of all WPF technology is giving us a kind of technology that can completely change the approach to design and code the UI. With the VMMV we can completely design an agnostic UI that doesn’t know the Model we are going to pass to it. Recycle, I will show you in...