CODEWITHSUNDEEP
c#.netasp.net-mvcasp.net-mvc-3
Basavaraj Hiremath
Basavaraj Hiremath

Reputation: 99

Getting null value in controller MVC3

I am newer to MVC3 and have a controller with one action.I defined some global properties in controller class and assigned values to those properties in action method. ex: 

  public class RosterController : Controller
   {
   int var1;
   int var2;
   int var3;
   public ActionResult Index(int param1)
   {
      if(param1 ==1)
      {
         return view(newRosterViewModel(var1+1,var2+2,var3+3));
      }
      else
      {
         var1=1;
         var2=2;
         var3=3;
         return view(newRosterViewModel(var1,var2,var3));
      }
      }
   }

In this code first time assigning values to var1,var2,var3. second time I need those vaues but values are null.

I tried with TempData but that also not holding value.

Upvotes: 2

Views: 250

Answers (4)

Richard
Richard

Reputation: 108975

but values are null.

I think you'll find their values are 0 (zero), this is the default value for integral fields.

Every request mapped to RosterController will cause a new instance of RosterController to be created, this avoids any issues with concurrent requests mixing up their controller state.

To persist information from one request to another there are many options (database, Session, cookies, Application, …), but the state of a controller instance is not one of them. The right approach to persistence across requests depends on the requirements.

Upvotes: 2

karaxuna
karaxuna

Reputation: 26930

When you render view you should pass this variables to controller again, because on every request controller is recreated:

public class RosterController : Controller
{
int var1 = 0;
int var2 = 0;
int var3 = 0;
public ActionResult Index(int param1, int var1, int var2, int var3)
{
  if(param1 ==1)
  {
     return view(newRosterViewModel(var1+1,var2+2,var3+3));
  }
  else
  {
     var1=1;
     var2=2;
     var3=3;
     return view(newRosterViewModel(var1,var2,var3));
  }
  }
}

Upvotes: 0

Yasser Shaikh
Yasser Shaikh

Reputation: 47774

You can make your variables static. Making your variables static means - thier lifetime extends across the entire run of the program.

declare static like this 

private static int var1;
private static int var2;
private static int var3;

But first please tell us your exact Use case

Upvotes: 1

dove
dove

Reputation: 20674

Why not make them static?

private static int var1;

or use Cache or Session

HttpRuntime.Cache.Add("var1", value);

var var1= HttpRuntime.Cache.Get("var1");

Upvotes: 1

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