I was wanting to ask the following about mvc to have a better understanding.
1 What is the difference between the way webforms and action controllers work.
2 How should one coming from a webforms background convert the page_load etc button clicks etc into mvc methods and events. Its this understanding that I am lacking.
3.How do i fill controls before I was used to setting the datasource but see allot of controls using the foreach on the front end is that really code separation?.
4 I will be developing a form designer in .net webforms I was used to using panels and loading controls but I see it will be neater in mvc by using partial views would that be my best course of action. I am a senior asp.net webforms developer with over ten years experience.
I have been watching plurisight videos but they center on using sql express not server.
A lot of help material you can get online about this topic.
Your first question about the way webforms and action controllers work -
In webform, you specify the code-behind file of your .aspx page and the code-behind file is the master of that page now. The browser hits the .aspx and the code behind file manages the work.
But in MVC, no view file is approached; the path is matched to the respective controller and action and the action handles it. Any controller can access the View of any other Controller. There are Shared Views which are common for every controller as well.
I strongly suggest you to read at this link and this codeproject article.
Some major points will be this :
You wont have the RAD (Rapid Application Development) environment i.e. the drag drop support for Controls, page viewer in case of Razor, etc.
You wont have the basic server controls Gridview, Repeater,etc in MVC. None of the controls in MVC are bind to any controller. You can neatly pick the desired elements using Javascript and play with them.
You get full control over the HTML
What I feel is that MVC is more flexible and jQuery-able as compared to Webforms
All the best!
Related
I've been watching a video on Scott Hanselmnn teaching MVC 2 tricks/tips. He mentions how MVC 2 by default uses ASP.NET Web Forms view engine to render the output of the views; he mentions that the web forms view engine is a little slower than it could be for MVC 2 since it generates a control tree and then outputs the HTML to the page (I hope I said that right).
I was wondering what he meant by web forms generating a code tree before outputting the HTML to the page. Does anyone have insight on the view engine of Web forms and the steps of the rendering process works for ASP.NET and MVC2?
In Web Forms, the HTML is generated by a hierarchy of controls, each of which needs to be called upon to render its HTML and each of which contributes to the Page ViewState. In addition, a lot of events are fired by Web Forms (Init, PreRender, etc) during its life cycle, and each control in the hierarchy also fires similar events.
In MVC, the process could theoretically be much simpler, as you don't have a deep hierarchy of controls, you don't have ViewState, and you don't have the need to fire events. However, MVC "piggybacks" off of the ASP.NET framework, and so behind the scenes, a lot of the Web Forms stuff is still there, although it's not needed.
ASP.Net WebForms was all built around the idea of "Faking" a persitent, stateful model around the stateless nature of HTTP. The idea was to give WinForms developers a familiar environment to work in, i.e. Controls, Events, Etc...
In order to do this, the markup is parsed into a collection of objects in memory that you can then reference like you would a control in WinForms:
TextBox.Text = "I hate viewstate!";
Each Control is added to a collection of Controls that represent the page to be sent back to the client. When it comes time to build the response, the engine walks through the tree collection of controls and asks each control to Render itself to the output stream. The result is what you get in the form of an HTTP Response.
In MVC this is an unnecessary step because those controls are never referenced. MVC embraces the stateless nature of the web, and instead maps posted form variables directly to Models for use by Controller Actions.
I'm working on an Asp.net website (it's been awhile) coming from an MVC background. How would I mimic partial views in Asp.net? Do I use web user controls or web part zones, or other?
ASP.NET is actually the base engine for both ASP.NET Webforms and ASP.NET MVC.
If you're used to MVC then you should really use ASP.NET MVC, where Partial Views are first class citizens.
Use ASP.NET MVC
To use one, you simply create a new MVC project, right click on the shared folder in the View folder, and select Add New View. From there you can select Partial View.
If you have to use Webforms
If you're stuck with webforms, then you use UserControls. The webforms model doesn't really translate well to the MVC paradigm, but UserControls are the closest things.
I think webparts are for Sharepoint only... ignore them.
User Controls are the ASP.NET WebForms equal of ASP.NET MVC Partial Views.
I would use Web User Controls. As far as I can tell they offer the same functionality. Plus the MVC implementation in ASP.NET uses them for partial views as well.
I assume you are using ASP.NET webforms and not ASP.NET MVC or this wouldn't be an issue. In webforms you can use UserControls (.ascx) to achieve a similar result.
One of the advantages of using user controls is you can interact directly with the details of the user control by exposing public properties and methods in the user control itself. You can make the user control have a lot of flexibility and have much of it's functionality defined by pure markup as well.
With partial views in MVC this is not really possible. I can't really think of anything you can't do with a user control that you can with a partial view in MVC. On the flip side there is ton of stuff a partial view can't do that a user control can.
Example of using a user control in a webforms project.
First add a reference to your user control at top of aspx page:
<%# Register Src="UserControls/PersonSearch.ascx" TagName="PersonSearch"
TagPrefix="uc1" %>
Then when you want to use it:
<uc1:PersonSearch hid="ucPersonSearch" runat="server">
</uc1:PersonSearch>
You can register events from you main page with the user control, expose properties, methods, etc...
For instance you could have a user control and register a notify event from your main page with the user control to get triggered once a person is selected. The user control just has to know about checking to see if a delegate has been registered and call it. This gives the container the ability to use the user control however it wants and leverage it's strength in unique ways.
It's more like a partial view on steroids but I 'partial' to user controls (pun intended) :)
I am trying to figure out how to use/create a custom control in ASP.NET MVC 2.
I created a custom control earlier and compiled it (ccontrol.dll), the control renders a div, textbox and a button + some javascript in order to post a comment on the website. It could be a static aspx page that i wanted to allow my visitors to add a comment to. I would then drag my control from the toolbar to the aspx page and run it, it would then render all the code needed on the webpage including fetching the data from a datasource and displaying that inside the div. The user could also just type in a comment and press the button to save it to the datasource.
Is this possible to convert to MVC 2? Any good tutorial that covers custom controls and MVC 2? (Ideally would be if the control could be made into a .dll file that i then could reuse on future webpages)
How do i write a custom control the mvc way? Any good tutorials on the topic?
You cannot design Custom Controls according the normal asp.net style because in Mvc there is no ViewState and there are no server side control events. Data are returned back to the server through a Model Binding process. The fact that rendering and filling data in are handled in separated pieces of code make difficult to implement complex server controls in Mvc.
However, I developed a theory, and also a toolset to make quite easily custom controls ina Mvc too in the full spirit of the Mvc paradigm i.e keeping separation of concerns between Views and Controllers. See My Codeplex project. There, you will find pointers to documentation and tutorials on my blog. If you need assistance feel free to contact me.
No it is not possible to use custom controls in ASP.NET MVC. you need to re-write in MVC way
I have developed a webapplication in both ASP.NET MVC and ASP.NET Webforms and i'm wondering isn't Webforms following the rules of the MVC Pattern just the as ASP.NET MVC is?
I mean we have the .aspx file which holds the visual (HTML and JavaScript) and then the code behind file which controls the user interaction and data for the .aspx file. Then we could make a Repository lager for fetching and doing stuff with data.
Isn't this the same as following the rules of the MVC Pattern? View for visual, Controller for controlling user interaction and data for the Views and the Model fetching and doing stuff with data?
I know ASP.NET MVC and Webforms handles Postbacks and URL handeling differently, but im not comparing the two ASP.NET techniques, but the MVC Pattern in generele for the two techniques.
ASP.NET Webforms is definitely not following the MVC pattern.
In MVC you have three elements, the Model, the View, and the Controller.
In ASP.NET Webforms, you have your Page (codebehind and the markup are compiled into a single object, not seperate), and whatever data is being shown. You really have no controller. You make a requrest directly to the page rather than a controller and the page is responsible for both working with the data and rendering the page. Definitely not seperated like MVC would be.
Just the fact that you're not using the codebehind in your aspx page should give you a hint that there are some pretty substantial differences between MVC and webforms... You aren't using the codebehind, are you?
Not to mention how hard it is to test a Webforms page.... You are testing your code, right?
You can indeed use an MVC pattern with Web Forms, but all you are doing is adding additional classes or layers to the postback. The previous answers here are coming from a purist point of view that is more clear separations built into the technology. But, there is nothing preventing you from using different classes to represent the Model the View and Controller and only have your WebForms bind to the View. All of the communication is still done on postback, but it is still technically MVC and still the correct pattern to use.
Reference:
http://msdn.microsoft.com/en-us/magazine/ff955232.aspx
Are there some things I cannot do with ASP.NET MVC?
Things that are only possible with ASP.NET WebForms,
or extremely much easier with WebForms?
We consider using ASP.NET MVC for a new project.
But I wonder if there are some obvious things we will not be able to do with ASP.NET MVC when compared to WebForms, or places where we will have to spend a lot of time with ASP.NET MVC.
The biggest one would be using existing 3rd party controls on your form. Most of the inbuilt controls are pretty easy to reproduce, but if you have a pet 3rd party control, you might have to host that on a regular (non-MVC) aspx page (luckliy this is supported).
Likewise, "web parts"
Also - the feature where ASP.NET uses different html for different clients (mobile, etc) becomes... different; you wouldn't want to do this by hand, but in reality most clients now work with standard html, so it is less of an issue in the first place.
Some things like i18n via resx files need extra work than is in the vanilla MVC template, but the samples are there on the internet.
One point... MVC is licensed only for MS/ASP.NET; so one thing you can't do (without violating the terms, as I understand it) is to run it in mono/Apache - but IANAL.
Now consider the things you can do with MVC, that you can't (or are hard) with vanilla:
routes instead of pages
automated input resolution (action arguments)
proper html control...
...enabling jQuery etc for simple AJAX
separation of concerns
testability
IoC/DI
multiple templating options (not just aspx/ascx)
re input resolution:
public ActionResult Show(string name, int? page, int? pageSize) {...}
will pick "name", "page" and "pageSize" off (any of) the route, query-string or form - so you don't have to spend lots of time picking out request values.
re templates - aspx/ascx aren't the only templating options. For example, see here; or you can write your own if you like... The view is not tied to ASP.NET controls at all.
Validation is not as easy as in WebForms. In Webforms you can add a validator and just set a property that enables clientside validation. You can localize the errormessage. The localization works clientside and serverside.
There is no out of the box clientside validation in MVC and you need to find a way to localize clientside errormessages.
Localization itself is different. Ressources obviously by default dont exist per page, because there is no page. But there is a good way to have ressources per view.
I still did not check, if it is possible to set SSL-required per folder.
EDIT
The story is different with MVC3. There is a good validation support now.
There are still things that are not implemented in MVC. The biggest issue for me is a complete implementation for donut cashing and partial cashing. There is some improvement in MVC3 in this area but it is still not complete. Anyway stay tuned: the MVC team seams to be aware that this is something they should work on.
The big one is Controls. User Controls are not available with ASP.NET MVC. I have even gone so far as to try using code like this:
new Label().RenderControl(...ResponseStream...);
No dice.
Of course, as a part of that, there is no need for view state, so that isn't in there.
Server controls do work, though.
As Marc said, third party tools and (serverside) webcontrols cannot be used. So slapping something together quickly by dragging and dropping a few controls on a form (like a grid and a dataaccess control) is no longer an option.
But with the codegeneration etc. you can still make something quickly. And you still have the above option if you need something quick.
I think view-state is non existent in MVC. You will have to track your own view state in some other way than the built in view-state in non MVC projects.
EDIT:
According to comments: "Getting rid of ViewState is an advantage not a disadvantage". – Craig
ASP.NET Ajax is not working with ASP.NET MVC so no UpdatePanel (due to lack of postback). Fortunately there is built-in ajax (Ajax.Form) which can be used to perform partial updates not to mention jQuery which is shipped by default with the Visual Studio project template.