C#•2y ago

❔ Session Variables

Storing what a user selects from a dropdown to a session variable but it gives a null error which should not be. looked for the error i know it lies here. tried for 2 days but no success. Just wondering is there another way to achieve my goal?

 cs  [HttpPost]
       public IActionResult Index(Student_List studentss)
        {
            int Studnentid = studentss.Stid;//problem is it is not showing the id or storing the id
            HttpContext.Session.SetInt32("Stid", Studnentid);//if i change studentid to 1 it works
            string studentname = studentss.StName;
            HttpContext.Session.SetString("StName", studentname);
            return RedirectToAction("Index", "Dashboard");
        }
    }
}

 cs  [HttpPost]
       public IActionResult Index(Student_List studentss)
        {
            int Studnentid = studentss.Stid;//problem is it is not showing the id or storing the id
            HttpContext.Session.SetInt32("Stid", Studnentid);//if i change studentid to 1 it works
            string studentname = studentss.StName;
            HttpContext.Session.SetString("StName", studentname);
            return RedirectToAction("Index", "Dashboard");
        }
    }
}

 cs
      @using (Html.BeginForm("Index", "Profile", FormMethod.Post))//new
    {
    <div class="form-control">
            <div class="col-md-3">
                @using (Html.BeginForm("",  "", FormMethod.Post))
                {
                    @Html.DropDownListFor(model => model.studlist, new SelectList(Model.studlist, "Stid", "StName")

                , new { @class = "form-control" })
                }
            </div>
            <button type="submit" class="btn btn-primary">Choose</button>
            </div>}

 cs
      @using (Html.BeginForm("Index", "Profile", FormMethod.Post))//new
    {
    <div class="form-control">
            <div class="col-md-3">
                @using (Html.BeginForm("",  "", FormMethod.Post))
                {
                    @Html.DropDownListFor(model => model.studlist, new SelectList(Model.studlist, "Stid", "StName")

                , new { @class = "form-control" })
                }
            </div>
            <button type="submit" class="btn btn-primary">Choose</button>
            </div>}

11 Replies

Pobiega•2y ago

And you have enabled sessions in your startup?

cake_combat•2y ago

Yes I have enabled sessions in my program.cs

Pobiega•2y ago

So by the comment "//if i change studentid to 1 it works", you mean if you hardcode the value to 1, what exactly works? that the session variable is updated? and if you don't, you get a null ref? on that line?

cake_combat•2y ago

It displays the person's id or name in another controller/index

Pobiega•2y ago

Okay, so there is nothing wrong with the session storage at all

cake_combat•2y ago

Yes

Pobiega•2y ago

its with your view model being weird My first suggestion would be to actually stick to a naming standard, preferably the official C# one Student_List is a bad class name, and even worse considering it doesnt seem to actually represent a list. (Should be StudentList, PascalCase). studentss has a typo in it. int Studnentid should be int studentId, no typo, camelCase. string studentname = studentss.StName; should be string studentName = students.StudentName;. camelCase local variable, no shortened name on the property. then, use the debugger to actually inspect the value you are getting for studentss. It appears to be null, which would mean the model binding failed or your frontend didnt actually send and form data.

cake_combat•2y ago

Student_list is a list in the model. Thank you so much i would work on the naming Ohhh thank you

Pobiega•2y ago

ah, but for a [HttpPost] endpoint, your method should take a single argument, a class object that represents the entire form payload

cake_combat•2y ago

I understand, i would implement the changes and pray it finally Smadge

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ Session Variables