TextBoxFor value is not updated after publication

Question

I have a simple strongly typed view, but I cannot update the text box in my form after posting.

Here is my model:

public class Repair { public string Number { get; set; } } 

And in my opinion this is a TextBox:

  @Html.TextBoxFor(x => x.Number) 

I am trying to update a text box after a message on my controller:

  [AcceptVerbs(HttpVerbs.Post)] public ActionResult Index(Repair r) { r.Number = "New Value"; return View(r); } 

Even if I set Number to a new value, the text in the text box does not change. What am I doing wrong?

Answer 1

Use ModelState.Clear() before setting the value

 [AcceptVerbs(HttpVerbs.Post)] public ActionResult Index(Repair r) { ModelState.Clear(); //Added here r.Number = "New Value"; return View(r); } 

Answer 2

When you send the model back to ActionResult and return the same view, the values ​​for the model objects are contained in the ModelState. ModelState is what contains valid / invalid field information as well as actual POSTED values. If you want to update the model value, you can do one of two things:

ModelState.Clear()

or

ModelState["Number"].Value = new ValueProviderResult("New Value", "New Value", CultureInfo.CurrentCulture)

Answer 3

From my relationship with the problem, I feel that this is a design error within the framework. IMO:

 @Html.TextBoxFor(x => x.Number) 

You should NOT take a value from ModelState , but rather directly from the model. At least it will be my expectation when I change the model and return View(model) .

 ModelState.Clear() 

is not an answer because it ModelState erasing ValidationSummary. Removing a key from ModelState not good because it removes the ValidationSummary for this key.

 ModelState["Number"].Value = new ValueProviderResult("New Value", "New Value", CultureInfo.CurrentCulture) 

is correct but too secret. Thus, in such cases, I prefer to use:

 <input type="text" name="Number" id="Number" value="@Model.Number"/> 

instead

 @Html.TextBoxFor(x => x.Number) 

Answer 4

If you find that ModelState.Clear () is too destructive, you can only target the element that you are changing, preserving the rest with ModelState.Remove ()

 [AcceptVerbs(HttpVerbs.Post)] public ActionResult Index(Repair r) { r.Number = "New Value"; ModelState.Remove("Number"); return View(r); } 

Also, it doesn't seem to matter with Remove () or Clear (), whether you call this method before updating the model or after

Answer 5

Try it. You can put it in the base controller if you want. This works well for me. This makes it so unobtrusive that it still works, but the values ​​from the model are displayed correctly, as EXPECTED.

 public class BaseController : Controller { public override void OnActionExecuted(ActionExecutedContext context) { ModelState.ToList().Select(x => x.Value).ToList().ForEach(x => { x.AttemptedValue = null; x.RawValue = null; }); // Do a bunch of stuff here if needed. Stuff like validation. base.OnActionExecuted(context); } }