The parameters dictionary contains a null entry for parameter id of non-nullable type System Int32

Question

I am building My first MVC application  I have a table in database containing 3 columns    Id   primary key Username password   When I am clicking on edit link edit a record  its throwing following exception      The parameters dictionary contains a null entry for parameter  id  of non-nullable type  System Int32  for method  System Web Mvc ActionResult Edit Int32   in  MvcApplication1 Controllers UserController   An optional parameter must be a reference type  a nullable type  or be declared as an optional parameter    Parameter name  parameters   Here is my edit code   public ActionResult Edit int id  User collection        UserDBMLDataContext db   new UserDBMLDataContext        var q   from abc in db User Login Details             where abc Id    id             select abc       IList lst   q ToList         User Login Details userLook    User Login Details lst 0        userLook Username   collection UserName      userLook Password   collection Password      db SubmitChanges        return RedirectToAction  Index

User · Answer

Just add Attribute routing if it is not present in appconfig or webconfig   config MapHttpAttributeRoutes

User · Answer

Just in case this helps anyone else  this error can occur in Visual Studio if you have a View as the open tab  and that tab depends on a parameter   Close the current view and start your application and the app will start  Normally   if you have a view open  Visual Studio interprets this as you want to run the current view

User · Answer

Is the action method on your form pointing to  controller edit 1   Try using one of these      the null in the last position is the html attributes  which you usually won t use    on a form   These invocations are kinda ugly Html BeginForm  Edit    User   new   Id   Model Id    FormMethod Post  null   Html BeginForm new   action  Edit   controller  User   id   Model Id      Or inside your form add a hidden  Id  field   Html HiddenFor m   gt  m Id

User · Answer

I was facing the Same Error    Solution  The name of the variable in the View through which we are passing value to Controller should Match the Name of Variable on Controller Side    csHtml  View      Html ActionLink  Edit    Edit    new   id item EmployeeId       cs  Controller Method      HttpGet              public ActionResult Edit int id                                EmployeeContext employeeContext   new EmployeeContext                    Employee employee   employeeContext Employees Where emp   gt  emp EmployeeId    id  First                    return View employee

User · Answer

Make the id parameter be a nullable int   public ActionResult Edit int  id  User collection    And then add the validation   if  Id    null

User · Answer

You get that error because ASP NET MVC cannot find an id parameter value to provide for the id parameter of your action method    You need to either pass that as part of the url     Home Edit 123    as a query string parameter    Home Edit id 123   or as a POSTed parameter  make sure to have something like  lt input type  hidden  name  id  value  123    gt  in your HTML form     Alternatively  you could make the id parameter be a nullable int  Edit int  id  User collection          but if the id were null  you wouldn t know what to edit

User · Answer

This might be useful for someone who has everything done right still facing issue  For them  above error may also cause due to ambiguous reference    If your Controller contains  using System Web Mvc    and also   using System Web Http    It will create ambiguity and by default it will use MVC RouteConfig settings instead of WebApiConfig settings for routing  Make sure for WebAPI call you need System Web Http reference only

User · Answer

You are expecting an id parameter in your URL but you aren t supplying one  Such as   http   yoursite com controller edit 12                                        missing

User · Answer

in your  WebApiConfig    Register    You have to change to  config Routes MapHttpRoute                  name   DefaultApi                   routeTemplate   api  controller   action   id                    defaults  new   id   RouteParameter Optional     Here the routeTemplate  is added with  action

User · Answer

This error means that the MVC framework can t find a value for your id property that you pass as an argument to the Edit method   MVC searches for these values in places like your route data  query string and form values    For example the following will pass the id property in your query string    Edit id 1   A nicer way would be to edit your routing configuration so you can pass this value as a part of the URL itself    Edit 1   This process where MVC searches for values for your parameters is called Model Binding and it s one of the best features of MVC  You can find more information on Model Binding here

User · Answer

I also had same issue  I investigated and found missing  action  attribute from route template   Before code  Having Issue    config Routes MapHttpRoute              name   DefaultApi               routeTemplate   api  controller   id                defaults  new   id   RouteParameter Optional                After Fix Working code    config Routes MapHttpRoute              name   DefaultApi               routeTemplate   api  controller   action   id                defaults  new   id   RouteParameter Optional

User · Answer

I had the same error  but for me  the issue was that I was doing the request with a wrong GUID  I missed the last 2 characters   360476f3-a4c8-4e1c-96d7-3c451c6c86 360476f3-a4c8-4e1c-96d7-3c451c6c865e

User · Answer

Just change your line of code to   lt a href    Required Edit id  item id  gt Edit lt  a gt    from where you are calling this function that will pass corect id

[c#] The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32'

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