I have recently read about the 3 tier architecture, and i would like to know how to apply it in developing Desktop Applications using WPF and C#.
any reference to external articles or resources is appreciated.
"3-tier architecture in WPF" instantly makes me answer you "MVVM - Model View View-Model"
This quick start tutorial can help you getting started with it.
I highly recommend working in MVVM with WPF anyway. I'd even say that, using WPF without working in MVVM does not make a lot of sense imho
You also have a more strict framework named PRISM, google it if you want
Anyway, for MVVM, a lot more anwers are listed in:
this thread
Related
Seeing as how MVVM is being highly regarded as a good system design pattern, I thought I might just jump aboard and give MVVM a shot.
Just a little background about myself before I begin with questions:
I have done a few years of development with ASP.NET Webforms. I have also done a fair bit of development in ASP.NET MVC, which I am quite comfortable with.
Currently, we have a number of "backbone" applications written using ASP.NET MVC 3 which we customize and sell to our clients whenever we're approached. These applications are all meant for internal use, hence plug-ins wouldn't be much of a problem.
The real problem with development is that for large scale business applications with complex business rules, ASP.NET MVC tends to slow us down (writing jQuery / javascript > server side processing > return result, use jQuery to notify > alter view, something along this line).
Then I began looking for answers that will help us improve our time to delivery and also responsiveness (well, we all know how JavaScript is capable of killing us) and my search brought me to Silverlight (we have the time to change, no worries there).
So here comes the questions:
I have come across many Silverlight MVVM samples online, but all of them show applications as simple as interacting with only one Database table. Is MVVM pattern well suited for large applications?
In MVC, I'm used to Dependency Injection from Ninject to pass an implementation of UnitOfWork to my Controller. In all samples I found online, none of them use any form of DI. Is it really unnecessary? Since the idea of MVVM is to decouple, so why not also decouple ViewModel from Model?
I've gone through a book published by Jeremy Likness called Designing Silverlight Business Applications. He used MEF to do the decoupling, which I think doesn't really fit into our application. We do not really need to do "hot-plugging". What's your take on this?
MVVM is all about Commands, Databindings and No Code-behinds. What if I want to interact with UIs that do not expose to commands? (I'm not too sure about this, I'm guessing ListView OnSelectionChange?)
To add to the previous answer:
We are developing a large corporate-wide Silverlight platform and a set of applications using MVVM. Seems to be working pretty well.
We are using DI extensively. Our system is built on top of Prism. Prism contains a large amount of sample applications of various complexity illustrating the use of DI in MVVM.
We use Unity as our IoC container. Prism contains guidance for both MEF and Unity. Unity seems to be a more traditional IoC approach.
In the vast majority of cases using Bindings and Commands covered our needs. For the others we use Expression Triggers and Actions. You can also create custom Triggers/Actions if necessary.
I have no answers for all your answers (never used MEF) but I can tell you my experience:
1- I've been in the development of a quite-large silverlight application and MVVM fits perfect to have a maintainable application. The bigger problems we had because of application size were because of Silverlight, not MVVM 8-)
2- I haven't used it too much but it's useful in many cases. There are several toolkits to use DI with Silverlight like MVVM Light Toolkit:
http://compiledexperience.com/blog/posts/blendable-mvvm-dependency-injection-and-unit-testing
4- For interaction between UIs you can use the Mediator pattern. The same MVVM Light Toolkit has a Messenger to subscribe, send and receive messages and maitain every layer decoupled.
Hope this helps you ;-)
I am learning to develop windows forms application with Entity Framework using Model View Presenter pattern, since it is the suggested design pattern for windows forms development on stackoverflow. On the other hand, there is a 'retired content' note on every article about MVP, on MSDN.
This is quite confusing, as I don't whether I should continue learning about MVP and try to implement it in windows forms development or there is another better design pattern that I should follow.
Any suggestion?
links:
http://msdn.microsoft.com/en-us/library/ff647543.aspx
http://msdn.microsoft.com/en-us/library/ff649820.aspx
For WinForms you should stick with MVP (Supervising Controller).
The reason you are seeing retired content is because Microsoft is heavily invested in the new Windows 8, Metro Style applications. WinRT built using C++, C# and WPF, or HTML5 + JavaScript are going to be what you will build applications in going forward, so it makes sense to learn at least one of those.
WinForms isn't officially deprecated, but don't expect it to get a lot of love from MS. I would spend some time learning XAML, and the MVVM pattern. That being said, the concepts for all UI design patterns (MVC, MVP, MVVM) are all very similar, so learning one will help you understand the others.
We have lots of project developed using .net 2.0 version if I want to convert those project to WPF then what will be the approach. Please discuss in detail.
to let the migration to WPF easy, be sure that your existing code doesnt contains a high coupling between GUI and your Business layer, if it's the case the most important step is to refactor your existing code, so your GUI code will contains only what's related to GUI.
And after this step the part of your project to migrate will be not the big one, it will concerns only the GUI logic.
When I did this kind of migration from winform to WPF , we spent more time to remove coupling between GUI and other layers than to migrate the GUI layer, due to high coupling betwn GUI and other layers.
Having gone through a similar exercise I'll tell you that it can be done but there are some challenges.
Step1: Just for clarification when we say WPF some people mean Silvelright / web. WPF is not Silverlight so you need to clarify I want to migrate existing applicaitons to WPF thick client applications. Since you stated WPF I am assuming you mean thich client/windows based applications so we'll go that route. (I'll mention SL at the end)
Step 2: Evaluate your projects from the code level for the most part refactoring the code is fairly easy. Since you are migrating from .net 2.0 to .net 4.0 I would really look at how many of your classes are defined, and see what can be refactored or in some isntances completely redesigned. THis leads us directly into step 3.
Step 3: Pick a design pattern. One of the tricky parts is coming to terms with a new design patterns such as MVVM for WPF. More than lilkely you will want to strip out and redesign the entire UI. As a result you will also want to utilize a proper design pattern (MVVM) or some flavor of that. This will also tie back to step two as some of your code will need to change to support your design pattern.
There are a ton of resources online for MVVM as well as UI development. If you are looking for reading materials I would look to WPF 4 unleashed as well as WPF illustrated. Both are good reads to help you get up to speed on the UI components how they work and the proper approach to using them in a project.
Get familar with .net 4 and the use of collections, types and of course the numerous new classes for wpf.
Disclaimer: You can in many instances create a WPF application usign tradition winform layout and practices. Whether this is right or wrong is a matter of opion of the developer. My personal opinion is that yes you can forego learning new design patterns and use a winform approach but you will not gain the full benefit and capabilities of the framework using this approach.
And finally if you are planning to migrate these apps to the web (silverlight) your work will be a little more of a challenge. Silvelright does have a little higer learning curve and there are a few more rules (security, asynchronous calls, web services etc) that must be learned, and followed. I have foudn that in creating a migration that it is easier to migrate from Siverlight to WPF that vice versa. As Microsoft continues to improve Sivelright I think we will get to the point to where the code is interchangeable between the two patterns however right now it's not there.
Conduct a search online but here are a few links to help you get started:
Scott Guthrie (Silverlight) http://weblogs.asp.net/scottgu/default.aspx
Josh Smith (WPF MVVM) http://joshsmithonwpf.wordpress.com/
best of luck
I'm working on Silverlight, of course I use MVVM. I found many problems but I can create work-around solution for them (some of these solution is not elegant at all), now I think it's time to bring some framework to help me.
I need functions that listed below.
Dependency Injection
Navigation
Callback
Messaging
Bind event to Command
Testability
As I know, there are many Framework out there, such as, Jounce, MVVMLight and Prism. I want to know which framework is suitable for my need?
When it comes to dependency injection I'd rather use MEF
which greatly simplifies code. As for the rest of the functions , currently I'm working with MVVMLight and I haven't faced any problem (although I'm not familiar with Jounce and Prism)
I think that you should consider the scale of the application. If it is a relatively small application that is unlikely to grow I would choose MVVMLight.
For a larger LOB application I would consider PRISM or Caliburn. I would also recommend reading blog posts by John Papa and Jeremy MIller on MVVM, Screens and Coordinators. Their ideas and insights helped enormously in a large scale Silverlight project I've built.
In WPF Prism is great, in Silverlight Jounce is the best by far. Its is very well integrated with MEF , very lightweight, elegant and stable. It also provides nice implementation to support complex events workflow scenarios, VisualStateManager in ViewModel (love that one), validation, debugging and unit testing; Used it in some quite complex projects and was happy I chose it.
I'm looking for code of full applications that (1) use the MVVM pattern and (2) are approachable for WPF/Silverlight/MVVM beginners. So far I have only found:
Crack.NET - A runtime debugging and scripting tool (useful but quite complicated)
CipherText - WPF Password Manager (perfect but written in VB.NET)
What are some others?
preferably smaller helper apps or tools that use MVVM but that have a completed feel, perhaps with WPF/Silverlight graphic/animation goodness, etc. which show not only the MVVM concepts being used but in a context of a real-world, completed application
My Contribution
Thanks for all the tips, I collected together a list of 15+ MVVM code examples and posted the here:
Overview of WPF/Silverlight code examples that help you learn MVVM.
I too class myself as a beginner in MVVM developing a large scale application for about a month now. I'm over most of the main hurdles, but keep getting confused up by a few things.
Be careful with the suggestions from Kent. They'll get you started, but the subtle differences in Silverlight and WPF will trip you up occasionally (triggers are one).
I don't know of any full sites, but I started with the Composite Application Guidance and PRISM libraries. These a little too cumbersome for a 'beginner' and just MVVM, but some of the concepts are very useful (event aggregator for example).
I suggest that you read blogs by Josh Twist, Josh Smith, Shaun Wildermuth and Nikhil Kothari. These guys are very knowledgeable. They are also very open to answering questions too.
What is your development background? Some of the concepts surrounding method calls, responses and delegation are a real break from "traditional sequential" coding techniques.
Given the question, you may be interested in the current effort going on to create a "Pet Shop" type reference implementation for M-V-VM. You can join the conversation or follow progress here.
I've been using MVVM for the last couple of months on a project and it's been fantastic. I've been doing UI work for over 12 years and it's the best thing I've come across.
I have been using MVVM for about 2 years now, and I can say that it is a resounding success. I have shipped one large-scale medical imaging solution using MVVM in Silverlight. I am also about to ship a complicated WPF application using Prism and MVVM extensively. In fact, I don't know how I'd achieve some of my problems elegantly without MVVM in this more recent application.
+1 on MVVM. It works. It is testable. It is extensible. It facilitates developer-designer workflows. It ALSO doesn't have to be messy and plumbing-heavy.
In addition, I created a medium-sized Silverlight application using MVVM for the CodeMash conference in January. You can see it and get the source code here.
Try this one. Also, Family.Show may be useful.
The WPF Disciples group has decided to create a real-world MVVM + Mediator reference application similar to the Pet Shop refence application for Web Apps. Your can follow the development on codeplex here