如何将HttpPost请求传递的Student对象存入本地List集合？

To persist your submitted Student records across requests without a database, you need a storage mechanism that survives controller instantiations (since controllers are created fresh for each request). Below are two practical approaches tailored to different use cases:

Approach 1: Static List (Shared Global Dataset) #

A static list keeps data alive as long as your application runs, but it’s shared between all users. This is the simplest option if you want a single, global collection of student entries.

Updated Controller Code #

public class StudentsController : Controller
{
    // Static list to retain data across controller instances
    private static List<Student> dbTempStudentList = new List<Student>();

    [HttpPost]
    public ActionResult Create(Student _student)
    {
        if (ModelState.IsValid)
        {
            // Add the submitted student to our in-memory collection
            dbTempStudentList.Add(_student);
            // Redirect to a view showing all stored students
            return RedirectToAction("Index");
        }
        // If validation fails, return to the form with the submitted data
        return View(_student);
    }

    // Optional: Action to display all stored students
    public ActionResult Index()
    {
        return View(dbTempStudentList);
    }
}

Approach 2: Session Storage (Per-User Isolation) #

Using Session ensures each user has their own independent list of students. This is better for multi-user apps where data should be isolated per session.

Updated Controller Code #

public class StudentsController : Controller
{
    [HttpPost]
    public ActionResult Create(Student _student)
    {
        if (ModelState.IsValid)
        {
            // Retrieve the user's list from Session, or create a new one if it doesn't exist
            List<Student> dbTempStudentList = Session["StudentList"] as List<Student> ?? new List<Student>();
            
            // Add the new student to the list
            dbTempStudentList.Add(_student);
            
            // Save the updated list back to Session
            Session["StudentList"] = dbTempStudentList;
            
            return RedirectToAction("Index");
        }
        return View(_student);
    }

    // Action to display the user's stored students
    public ActionResult Index()
    {
        // Get the user's list from Session (or empty list if none exists)
        var studentList = Session["StudentList"] as List<Student> ?? new List<Student>();
        return View(studentList);
    }
}

Note: Session is enabled by default in ASP.NET MVC, but if you’ve disabled it, you’ll need to re-enable it in your application configuration.

Student Entity Class (Unchanged) #

Your existing Student class works perfectly for this use case:

public class Student 
{ 
    public int StudentID { get; set; } 
    public string StudentName { get; set; } 
    public string StudentLastName { get; set; } 
    public string Creditbalance { get; set; } 
    public string CurrentBalance { get; set; } 
}

Add an Index View to Display Stored Students #

To visualize the stored data, create an Index.cshtml view in the Views/Students folder:

@{
    ViewBag.Title = "Stored Students";
}

<h2>Stored Students</h2>

<p>
    @Html.ActionLink("Add New Student", "Create")
</p>

<table class="table">
    <thead>
        <tr>
            <th>@Html.DisplayNameFor(model => model.StudentID)</th>
            <th>@Html.DisplayNameFor(model => model.StudentName)</th>
            <th>@Html.DisplayNameFor(model => model.StudentLastName)</th>
            <th>@Html.DisplayNameFor(model => model.Creditbalance)</th>
            <th>@Html.DisplayNameFor(model => model.CurrentBalance)</th>
        </tr>
    </thead>
    <tbody>
        @foreach (var student in Model)
        {
            <tr>
                <td>@Html.DisplayFor(item => student.StudentID)</td>
                <td>@Html.DisplayFor(item => student.StudentName)</td>
                <td>@Html.DisplayFor(item => student.StudentLastName)</td>
                <td>@Html.DisplayFor(item => student.Creditbalance)</td>
                <td>@Html.DisplayFor(item => student.CurrentBalance)</td>
            </tr>
        }
    </tbody>
</table>

Key Notes #

• Data Persistence: Both approaches store data in memory, so all entries will be lost if your application restarts (e.g., during deployment or server reset).
• Static List: Use this only if you want a shared, global dataset accessible to all users.
• Session: Ideal for scenarios where each user should manage their own independent set of student entries.

内容的提问来源于stack exchange，提问作者Maria Perez