C#•3y 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  [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>}

 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>}

Pobiega•2/9/23, 10:40 AM

And you have enabled sessions in your startup?

cake_combatOP•2/9/23, 10:50 AM

Yes I have enabled sessions in my program.cs

Pobiega•2/9/23, 11:03 AM

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?

Pobiega•2/9/23, 11:03 AM

and if you don't, you get a null ref? on that line?

cake_combatOP•2/9/23, 11:10 AM

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

Pobiega•2/9/23, 11:12 AM

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

PPobiega and if you don't, you get a null ref? on that line?

cake_combatOP•2/9/23, 11:12 AM

Yes

Pobiega•2/9/23, 11:12 AM

its with your view model being weird

Pobiega•2/9/23, 11:14 AM

My first suggestion would be to actually stick to a naming standard, preferably the official C# one

Pobiega•2/9/23, 11:16 AM

Student_ListStudent_List is a bad class name, and even worse considering it doesnt seem to actually represent a list. (Should be StudentListStudentList, PascalCase).
studentssstudentss has a typo in it.
int Studnentidint Studnentid should be int studentIdint studentId, no typo, camelCase.
string studentname = studentss.StName;string studentname = studentss.StName; should be string studentName = students.StudentName;string studentName = students.StudentName;. camelCase local variable, no shortened name on the property.

Pobiega•2/9/23, 11:17 AM

then, use the debugger to actually inspect the value you are getting for studentssstudentss. It appears to be null, which would mean the model binding failed or your frontend didnt actually send and form data.

PPobiega `Student_List` is a bad class name, and even worse considering it doesnt seem to...

cake_combatOP•2/9/23, 11:22 AM

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

PPobiega then, use the debugger to actually inspect the value you are getting for `studen...

cake_combatOP•2/9/23, 11:22 AM

Ohhh thank you

Pobiega•2/9/23, 11:23 AM

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

cake_combatOP•2/9/23, 11:28 AM

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