I'm very much new to using the MVC Pattern but what I'm trying to do is have a user input some numbers and then each time they submit a number it'll be added to a list. However the list gets wiped between button presses, I currently have all the list stuff in the controller.
Controller
public class NumberController : Controller
{
List<int> numList = new List<int>();
// GET: Number
public ActionResult Index()
{
return View();
}
[HttpPost]
public ActionResult ProcessNumber(Number number)
{
int RNo = number.RNum;
numList.Add(RNo);
string sequenceList = "";
foreach (int num in numList) { sequenceList = sequenceList + ", " + num; }
ViewBag.Message = "Number " + RNo + " saved successfully!" + " This is your current sequence :" + sequenceList + " A total of " + numList.Count + "numbers.";
return View("Index");
}
}
Then over in the View I have this.
@model TechMVC.Models.Number
@{
ViewBag.Title = "Index";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>Index</h2>
@using (Html.BeginForm("ProcessNumber", "Number", FormMethod.Post))
{
@Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Number</h4>
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
<div class="form-group">
@Html.LabelFor(model => model.RNum, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.RNum, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.RNum, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Create" class="btn btn-default" />
<p>@ViewBag.Message</p>
</div>
</div>
</div>
}
Which comes out looking like this :
I'm not interested in making it look fancy, I'm just still not overly certain of the MVC framework. I get that I've sent Data here from a user to the view and then to the controller but have I also used the model at some point? Should I store the list in the model or in the view?
You cannot retain these values in a controller variable. The Web is stateless, and each HTTP request executes a new instance of your code. So you'll need to persist your data somewhere.
You could utilize the Session State or Application State for that matter. For more reading:
In a real-world application you'll definitely need a database storage. doesn't matter which store, you could use Sqlite, SQL Server, MySQL, XML documents or anything you want. If you're new to .NET Web Development I suggest you get started with Entity Framework for your data access needs. more information:
You must store your data somewhere. For example you can store it in a session
List numList = null; int rNo = number.RNum; string sequenceList = string.Empty;
if (Session["NumList"] != null) { //session exist. set numList = session numList = Session["NumList"] as List<int>; } else { //session not exist. set numList as new numList = new List<int>(); } //add number to numList numList.Add(rNo); //set session = numList Session["NumList"] = numList; //make join oj numList sequenceList = String.Join(", ", numList.ToArray()); //set message in a ViewBag ViewBag.Message = $"Number {rNo} saved successfully!" + $" This is your current sequence : {sequenceList}" + $" A total of {numList.Count} numbers."; return View("Index");
I'm without Vs so can be errors
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