i want dynamically create ascx files, to partial render them.
but as i know, ot show them , i at least need dummy method:
public ActionResult test()
{
return PartialView();
}
how can i create this method for each new ascx file?
upd: i need factory?
Why would you create dynamic ascx files?
If you want to create all the layout in the controller you should be able to return it directly.
But then, why would you do that?
This way it will be really hard to do unit testing and refactoring and reuse.
You'd need to create your .ascx controls ahead of time. If you are doing this, I would recommend that you register a new view engine to provide a new PartialView location.
public class MyViewEngine : WebFormsViewEngine
{
public MyViewEngine()
{
PartialViewLocationFormats = new[]
{
"~/Views/{1}/{0}.ascx",
"~/Views/GeneratedControls/{0}.ascx",
"~/Views/Shared/{0}.ascx"
};
}
}
This allows you to write your dynamic views to the /Views/GeneratedControls/ folder. If you need to use a specifically named control (i.e. the control you generate has a random name) then you simply need to adjust your call to PartialView:
public ActionResult test()
{
return PartialView("name-of-control");
}
Otherwise MVC will use the name of the Action as the name of the control to use.
Related
I have my _Layout.cshtml file that uses the ViewBag model to render some dynamic content.
I understand ViewBag can be populated in the controller and accessed in the view and/or layout page.
My question is, if my Layout page is using #ViewBag.SiteName, I want to avoid having to set this variable in each controller before I return the view. Is there a way to set this variable on a global level? Or how else should I pass this data to the layout page?
If you set anything in ViewBag - this happens after the Layout has been rendered -
You've missed the boat.
As others have mentioned, you can create a "helper" controller:
public class LayoutController : BaseController
{
[ChildActionOnly]
public ActionResult SiteName()
{
return new ContentResult {Content = "Site name goes here"};
}
}
Then, in your layout:
#{Html.Action("SiteName", "Layout")}
Is that possible to use viewstart only for a particular controller and view?
I was using only _Layou.cshtml file inside views folder.
Now i added _ViewStart.cshtml as common view inside views folder and moved _Layout to Shared folder.
This is program structure:
Homecontroller
public ActionResult Index()
{
return View();
}
Index.cshtml
#{
Layout = "~/Views/_Layout.cshtml";
}
_Layout.cshtml
{
//design code for Index.chtml
}
as per the above code, _Layout rendered for homecontroller .
When done the changes mentioned at the very first line, I'm getting the controls inside _Layout.cshtml in every controller I use.
I use nearly 6 controllers.
How to make this change without disturbing the entire code.
Please help.
PS: I need to introduce _ViewStart into the program since I'm integrating openid with my already developed project.
You can create another _ViewStart.cshtml (in Views/[controller] a sub-folder for example) that will override the root one, something like:
#{ Layout = null; }
You can simply use the ViewBag to determine whether to use Layout or not:
public ActionResult AnotherAction()
{
....
ViewBag.NoLayout = true;
return View();
}
and in your _ViewStart:
#{
if (ViewBag.NoLayout == null || !ViewBag.NoLayout)
Layout = "~/Views/_Layout.cshtml";
}
You can read more about MVC3 Razor layouts on Scott Guthrie's Blog
I want to make a new project and I want to add a new page, using the Microsoft sample website as a starting point. The Microsoft sample website already has an About and a Contact page.
How do I add a new page to the sample website using ASP.NET mvc4?
In ASP.NET MVC you work with Models, Controllers and Views. Controllers are classes containing methods called Actions. Each Action is used as an entry point for a given user request. This Action will perform any necessary processing with the model and return a view. So basically you will start with defining a Controller (if not already done) and add Actions to it:
public class HomeController: Controller
{
public ActionResult Index()
{
return View();
}
public ActionResult SomeAction()
{
return View();
}
}
Then you right click on the Action name and select the Add->View option which will create a new View for the given Action in the respective ~/Views folder.
I would recommend that you start by going through the basic tutorials here: http://asp.net/mvc
How can I create an individual controller and model for a partial view? I want to be able to place this partial view any where on the site so it needs it's own controller. I am current rendering the partial as so
#Html.Partial("_Testimonials")
Why not use Html.RenderAction()?
Then you could put the following into any controller (even creating a new controller for it):
[ChildActionOnly]
public ActionResult MyActionThatGeneratesAPartial(string parameter1)
{
var model = repository.GetThingByParameter(parameter1);
var partialViewModel = new PartialViewModel(model);
return PartialView(partialViewModel);
}
Then you could create a new partial view and have your PartialViewModel be what it inherits from.
For Razor, the code block in the view would look like this:
#{ Html.RenderAction("Index", "Home"); }
For the WebFormsViewEngine, it would look like this:
<% Html.RenderAction("Index", "Home"); %>
It does not need its own controller. You can use
#Html.Partial("../ControllerName/_Testimonials.cshtml")
This allows you to render the partial from any page. Just make sure the relative path is correct.
If it were me, I would simply create a new Controller with a Single Action and then use RenderAction in place of Partial:
// Assuming the controller is named NewController
#{Html.RenderAction("ActionName",
"New",
new { routeValueOne = "SomeValue" });
}
The most important thing is, the action created must return partial view, see below.
public ActionResult _YourPartialViewSection()
{
return PartialView();
}
You don't need a controller and when using .Net 5 (MVC 6) you can render the partial view async
#await Html.PartialAsync("_LoginPartial")
or
#{await Html.RenderPartialAsync("PartialName");}
or if you are using .net core 2.1 > you can just use:
<partial name="Shared/_ProductPartial.cshtml"
for="Product" />
Html.Action is a poorly designed technology.
Because in your page Controller you can't receive the results of computation in your Partial Controller. Data flow is only Page Controller => Partial Controller.
To be closer to WebForm UserControl (*.ascx) you need to:
Create a page Model and a Partial Model
Place your Partial Model as a property in your page Model
In page's View use Html.EditorFor(m => m.MyPartialModel)
Create an appropriate Partial View
Create a class very similar to that Child Action Controller described here in answers many times. But it will be just a class (inherited from Object rather than from Controller). Let's name it as MyControllerPartial. MyControllerPartial will know only about Partial Model.
Use your MyControllerPartial in your page controller. Pass model.MyPartialModel to MyControllerPartial
Take care about proper prefix in your MyControllerPartial. Fox example: ModelState.AddError("MyPartialModel." + "SomeFieldName", "Error")
In MyControllerPartial you can make validation and implement other logics related to this Partial Model
In this situation you can use it like:
public class MyController : Controller
{
....
public MyController()
{
MyChildController = new MyControllerPartial(this.ViewData);
}
[HttpPost]
public ActionResult Index(MyPageViewModel model)
{
...
int childResult = MyChildController.ProcessSomething(model.MyPartialModel);
...
}
}
P.S.
In step 3 you can use Html.Partial("PartialViewName", Model.MyPartialModel, <clone_ViewData_with_prefix_MyPartialModel>). For more details see ASP.NET MVC partial views: input name prefixes
I am migrating a web site to a new one using ASP .NET MVC2.
In the original site, master page has code-behind to check a query string parameter value. Depending on this value, code-behind dynamically modify some CSS property to hide / display master page elements.
As MVC2 has no code-behind because we are supposed to perform everything in the controllers, how should I proceed in this case ?
I see this : asp.net mvc modifying master file from a view
It partially answers my needs but the query string processing is common to all pages. How can I move this processing in a common code section ?
Regards.
A helper method looks like a good place:
public static class HtmlHelperExtensions
{
public static string GetCss(this HtmlHelper htmlHelper)
{
// read some request parameter
// here you also have access to route data so the
// parameter could be part of your custom routes as well
var foo = htmlHelper.ViewContext.HttpContext.Request["foo"];
// based on the value of this parameter
// return the appropriate CSS class
return (foo == "bar") ? "barClass" : "fooClass";
}
}
And somewhere in your master page:
<body class="<%= Html.GetCss() %>">
Or if you are always going to apply it to the body tag only it might be more appropriate to do this in order to reduce the tag soup:
public static class HtmlHelperExtensions
{
public static MvcHtmlString StartBody(this HtmlHelper htmlHelper)
{
var body = new TagBuilder("body");
var foo = htmlHelper.ViewContext.HttpContext.Request["foo"];
var bodyClass = (foo == "bar") ? "barClass" : "fooClass";
body.AddCssClass(bodyClass);
return MvcHtmlString.Create(body.ToString(TagRenderMode.StartTag));
}
}
and in your master page at the place of the body tag:
<%= Html.StartBody() %>
I can think of two solutions to this:
Derive your controllers from one controller base and set the ViewData parameter there depending on posted Form values
Don't use ViewData at all, but simply look for the form value in the view (using HttpContext.Current)
The second method violates the MVC pattern. IMO it is still acceptable in some scenarios, for example I am using this approach to highlight the currently selected item in a navigation menu.