How fix not working ActionResult Update in NET Core? - asp.net-core

Question

I'm learning about .NET Core and I'm using code from this tutorial. But my update sql is not working.
Here is the index view code:
public ActionResult Index(int? id)
{
ViewBag.Operation = id;
ViewBag.Name = db.Chars.ToList();
Chars Chars = db.Chars.Find(id);
return View(Chars);
}
As for now it work I see results from sql and here is the updated part:
public ActionResult Update(Chars Chars)
{
if (ModelState.IsValid)
{
db.Entry(Chars).State = EntityState.Modified;
db.SaveChanges();
}
return RedirectToAction("Index", new { id = 0 });
}
Here is index.cshtml part:
#using (Html.BeginForm()
{
#foreach (var item in (IEnumerable<MVC__test_2.Chars>)ViewBag.Name)
{
<div class="form-group">
<div class="col-md-10">
#Html.EditorFor(modelItem => item.CharName, new { htmlAttributes = new { #class = "form-control" } })
#Html.HiddenFor(modelItem => item.CharID, new { id = item.CharID })
</div>
</div>
#Html.ActionLink("Index", "Index", new { id = item.CharID })
<input type="submit" value="Update" name="Update"
style=#((ViewBag.Operation != null && Convert.ToInt32(ViewBag.Operation) > 0) ? "display:block" : "display:none") />
}
}

Answer 1

According to the tutorial you provided , I made a demo to test and it updated the data well. The following is the working example , you could refer to and make the modification as per your need .
Model
public class Description
{
public int Id { get; set; }
public string Display { get; set; }
}
Controller
public IActionResult Index(int? id)
{
ViewBag.Operation = id;
ViewBag.Name = _context.Description.ToList();
Description description= _context.Description.Find(id);
return View(description);
}
public ActionResult Update(Description description)
{
if (ModelState.IsValid)
{
_context.Entry(description).State = EntityState.Modified;
_context.SaveChanges();
}
return RedirectToAction("Index", new { id = 0 });
}
Index.cshtml , you should hide the id of the modified data in the modification section.
#model WebApplication1.Models.Description
#using (Html.BeginForm("Update", "Home", FormMethod.Post))
{
#foreach (var item in (IEnumerable<WebApplication1.Models.Description >)ViewBag.Name)
{
<div class="form-group">
<div class="col-md-10">
#Html.EditorFor(modelItem => item.Display, new { htmlAttributes = new { #class = "form-control" } })
#Html.HiddenFor(modelItem => item.Id, new { id = item.Id })
</div>
</div>
#Html.ActionLink("Edit", "Index", new { id = item.Id })
}
// Create or Update data
#Html.AntiForgeryToken()
<div class="form-horizontal">
#Html.ValidationSummary(true)
<fieldset>
<legend> <b>Entry Screen</b></legend>
<div class="form-group">
#Html.LabelFor(model => model.Display, new { #class = "control-label col-md-2" })
#Html.HiddenFor(model => model.Id)
<div class="col-md-10">
#Html.EditorFor(model => model.Display)
#Html.ValidationMessageFor(model => model.Display)
</div>
</div>
<div class="form-group">
<p>
<input type="submit" value="Create" name="Create"
style=#((ViewBag.Operation != null && Convert.ToInt32(ViewBag.Operation) > 0) ? "display:none" : "display:block") />
<input type="submit" value="Update" name="Update"
style=#((ViewBag.Operation != null && Convert.ToInt32(ViewBag.Operation) > 0) ? "display:block" : "display:none") />
</p>
</div>
</fieldset>
</div>
}