I set a Application variable in my global.asa.cs with:
protected void Application_Start()
{
...
/开发者_JAVA百科/ load all application settings
Application["LICENSE_NAME"] = "asdf";
}
and then try to access with my razor view like this:
@Application["LICENSE_NAME"]
and get this error:
Compiler Error Message: CS0103: The name 'Application' does not exist in the current context
what is the proper syntax?
Views are not supposed to pull data from somewhere. They are supposed to use data that was passed to them in form of a view model from the controller action. So if you need to use such data in a view the proper way to do it is to define a view model:
public class MyViewModel
{
public string LicenseName { get; set; }
}
have your controller action populate it from wherever it needs to populate it (for better separation of concerns you might use a repository):
public ActionResult Index()
{
var model = new MyViewModel
{
LicenseName = HttpContext.Application["LICENSE_NAME"] as string
};
return View(model);
}
and finally have your strongly typed view display this information to the user:
<div>@Model.LicenseName</div>
That's the correct MVC pattern and that's how it should be done.
Avoid views that pull data like pest, because today it's Application state, tomorrow it's a foreach
loop, next week it's a LINQ query and in no time you end up writing SQL queries in your views.
@HttpContext.Current.Application["someindex"]
You can get the current Application using the automatically generated ApplicationInstance
property:
@ApplicationInstance.Application["LICENSE_NAME"]
However, this logic does not belong in the view.
You should be able to access this via HttpContext.Current.Application[]
, however MVC best practices would state that you should probably consider passing this through your View Model.
Building on @Darin-Dimitrov pattern answered above, I passed a model into a partial view, which I loaded into a _Layout page.
I needed to load a web page from an external resource on Application Load, which will be used as the header navigation across multiple sites. This is in my Global.asax.cs
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
Application["HeaderNav"] = GetHtmlPage("https://site.com/HeaderNav.html");
}
static string GetHtmlPage(string strURL)
{
string strResult;
var objRequest = HttpWebRequest.Create(strURL);
var objResponse = objRequest.GetResponse();
using (var sr = new StreamReader(objResponse.GetResponseStream()))
{
strResult = sr.ReadToEnd();
sr.Close();
}
return strResult;
}
Here is my controller Action for the partial view.
public class ProfileController : BaseController
{
public ActionResult HeaderNav()
{
var model = new Models.HeaderModel
{
NavigationHtml = HttpContext.Application["HeaderNav"] as string
};
return PartialView("_Header", model);
}
}
I loaded the partial view in the _Layout page like this.
<div id="header">
@{Html.RenderAction("HeaderNav", "Profile");}
</div>
The partial view _Header.cshtml is very simple and just loads the html from the application variable.
@model Models.HeaderModel
@MvcHtmlString.Create(Model.NavigationHtml)
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RouteConfig.RegisterRoutes(RouteTable.Routes);
var e = "Hello";
Application["value"] = e;
}
@HttpContext.Current.Application["value"]
I had this issue in an MVC controller and had to make fully qualified HttpContext for it to work ..
System.Web.HttpContext.Current.Application["VarName"]
精彩评论