将值分配给数组时，它返回 Object 引用未设置为 object 的实例

Question

So basically I am trying to get the value from the database and form it into a list so that I can assign each one of them to a dynamic input tag.
View

@foreach (var item in (List<SelectListItem>)ViewBag.AppendTab)
{
@Html.TextBoxFor(m => m.Name[Convert.ToInt32(item.Text)],
new { id = "txtName-" + item.Value, placeholder = "", @class = "form-control"})
@Html.TextBoxFor(m => m.PhoneNo[Convert.ToInt32(item.Text)],
new { id = "txtPhoneNo-" + item.Value, placeholder = "", @class = "form-control"})
/* And Many others field */

}

Controller

List<Student> Model = _StudentBLL.GetAll(SchoolId); // Action that gets the list

if (Model.Count != 0)
{
    int counter = 0;
    foreach (var item in Model)
    {
        view.Name[counter] = item.Name;
        view.PhoneNo[counter] = item.PhoneNo;
        
        counter++;
    }
    
}

Answer 1

@Beingnin It is referring to this line view.Name[counter] = item.Name; – FENR1R Ace 2 hours ago View.Name is not null – FENR1R Ace 1 hour ago

If nothing on the left hand side of the = is null then it must be that your GetAll put a null thing in the Model. This model, for example, will also crash with a null reference in the same way:

List<Student> Model = new List<Student>();
Model.Add(null);

How it gets there, is for you to figure out.. You could just exclude them:

foreach (var item in Model.Where(s => s != null))

.. but you should try and find out why they're happening in the first place, so it doesn't trip you up elsewhere in the code when you use GetAll again.

Ultimately, NullRef exceptions are typically very easy to debug; the code crashes and stops, the debugger opens and you just point to every word, or select highlight every expression and then point to it, on the line with your mouse, see which one makes the tooltip say "null". You can also open the immediate window and paste bits of the code line into it and run it, looking for where it says null, eg pasting ?item into it should say null in your case