ASP.NET MVC 3 LINQ中的结果集过滤

Question

Say i've a action of a controller like

   IList <post> p =db.posts.Include("user").ToList();


        if (Request.Form["searchString"] != null)          
        {
            if ((p!=null) && (p.Any()))

            {
                p =(p.Where(a=>a.area==Request 
                .Form["searchString"]).Tolist();                                
            }
       }           
        if (Request.Form["searchString2"] != null)          
        {              
            if ((p!=null) && (p.Any()))

            {


            p=(p.Where(a=>a.city==Request 
          .Form["searchString2"]).Tolist();                                            
            }
        }  
      return View(p);

here first i've get a resultset(p). then i want to filter p by some criterias.it gives error for the ToList() inside the condition block. error: there is no definition for tolist() in the post

Answer 1

it would be:

 if ((rs!=null) && (rs.Any()))
     {
     rs = (from posts1 in rs where                   
     posts1.area="Dhaka").ToList() ;                             
     }

just consider that if you call . ToList() or Any it will go to DB (in case you are using a ORM)

Answer 2

var filteredRS=rs.Where(s=>s.area=="Dhaka").ToList();

Answer 3

You could filter directly:

List <student> rs = db.students.Where(student => student.area == "Dhaka").ToList();

or:

List <student> filtered = rs.Where(student => student.area == "Dhaka").ToList();