controllersactions-110711131108-phpapp01

7/31/2019 controllersactions-110711131108-phpapp01

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Controllers &

Actions in MVC

Eyal VardiCEO E4D Solutions LTDMicrosoft MVP Visual C#

blog: www.eVardi.com


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2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: [email protected]

Agenda

Controllers Overview

ViewData vs. ViewBag

Action & ActionResult

Controller Attributes

Async Controller


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Understanding Controllers

MVC controllers are responsible forresponding to requests made against anASP.NET MVC website.


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The Controller Responsibility

Execute the right action method andvalidating that it can be called.

Getting the values to use as the action

method's arguments.

Handling all errors that might occur during theexecution of the action method.

Providing the default WebFormViewEngineclass for rendering ASP.NET page types(views).


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Controller Sample

http://E4D.co.il / Course / Net / MVC / http://E4D.co.il / Course/ Net ? name=MVC

publicclassCourseController : Controller

{

publicActionResult Net( string name )

{

var course = BL.GetCourse(name);

return View( course );}

}


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ViewData Property

Used to set view-specific data in adictionary object that can hold multiplename/value pairs.


{


{

ViewData["Course"] = BL.GetCourse(name);

return View();}

}


7/19 2010 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: [email protected]

ViewBag Property

Used to set view-specific data in adictionary object that can hold multiplename/value pairs.


{


{

ViewBag.Course = BL.GetCourse(name);

return View();}

}



Actions

Action == Method

Action must meet certain requirements:

Must be public.

Cannot be a static method.

Cannot be an extension method.

Cannot have open generic types.

The method is not a method of the controller base class.

The method cannot contain ref or out parameters.


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Action Results

A controller action returnssomething called an action result.

Action results types:

ViewResult

EmptyResult

RedirectResult

JsonResult

JavaScriptResult

ContentResult

FileContentResult

FilePathResult

FileStreamResult

HttpNotFoundResult

HttpRedirectResult

HttpStatusCodeResult



Controller View Methods

Normally, you do not

return an action result

directly. Instead, youcall one of the following

methods of the

Controller base class.



Controller ViewMethods



Controller Class



Controller Attributes

[ActionName]

[NonAction]

[AcceptVerbs]

[HttpGet]

[HttpPost]

[HttpPut]

[HttpDelete]

[ChildActionOnly]

[SessionState]

[OutputCache]



SessionState Attribute

Using the attribute, you can completely turnon or off session state, adjust it to read-only,or make it required. Default, Required, ReadOnly & Disabled.

[SessionState( SessionStateBehavior.Disabled )]

publicclassHomeController : Controller

{

publicActionResult Index()

{

Session["E4D"] = "E4D Learning";

return View();

}

}



OutputCache Attribute

[ChildActionOnly][OutputCache( Duration = 20 )]

publicActionResult CurrentTime()

{

return PartialView();

}

OutputCache Sample

View Time: @DateTime.Now.ToString("h:mm:ss")

Partial View Time:

@{

Html.RenderAction("CurrentTime");

}



Async Controller

The AsyncControllerclass enables you towrite asynchronous action methods.



Async Action

publicclassPortalController : AsyncController{

[AsyncTimeout(Duration = 5000 )]

publicvoid NewsAsync(string city)

{

AsyncManager.OutstandingOperations.Increment();

NewsService newsService = new NewsService();

newsService.GetHeadlinesCompleted += (sender, e) =>

{

AsyncManager.Parameters["headlines"] = e.Value;

AsyncManager.OutstandingOperations.Decrement();

};

newsService.GetHeadlinesAsync(city);

}publicActionResult NewsCompleted(NewsHeadline[] headlines)

{

return View( "News",

newViewStringModel { Headlines = headlines } );

}

}

Async Action


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Async Action

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