How to add alert class in viewbag from controller - asp.net-mvc

Question

Here i am trying to add bootstrap alert class to the exception shown in ViewBag.message from controller on clicking the create button. But adding the class shows the exception 'string' does not contain a definition for 'cssClass'.
Below Is Create.cshtml
#model WebApplication8.Models.Info
#{
ViewBag.Title = "Create";
}
<h2>Create</h2>
<div class="errormsg">
#ViewBag.message
</div>
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Info</h4>
<hr />
#Html.ValidationSummary(true, "", new { #class = "text-danger" })
<div class="form-group">
#Html.LabelFor(model => model.name, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.name, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.name, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.des, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.des, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.des, "", 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" />
</div>
</div>
</div>
}
<div>
#Html.ActionLink("Back to List", "Index")
</div>
#section Scripts {
#Scripts.Render("~/bundles/jqueryval")
}
Below is Create Action Method In controller
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "id,name,des")] Info info)
{
try
{
if (ModelState.IsValid)
{
db.create(info);
return RedirectToAction("Index");
}
}
catch (Exception ex)
{
ViewBag.message = ex.Message;
ViewBag.message.cssClass = "alert alert-danger";
return View(info);
}
return View(info);
}
below is Interface Implementer class
public class StudentInfo : IStudentInfo
{
private AbcdEntities db1 = new AbcdEntities();
public void create(Info info)
{
if (info.name!=null)
{
if (info.des!=null)
{
db1.Infoes.Add(info);
db1.SaveChanges();
}
else
{
throw new Exception("Des Cannot Be Empty");
}
}
else
{
throw new Exception("Name Cannot Be Empty");
}
}

Answer 1

ViewBag.message = ex.Message;
You assign to the ViewBag a property message passing to it the Exception.Message, a simple string.
ViewBag.message.cssClass = "alert alert-danger";
Then you try to access a non existent property of a string.
I think you need to understand better the usage of the viewBag, of dynamics, and in wich way MVC propose his way to work on views with Razor.
If you want a complex object in the viewBag you need to create something similar with a dynamic:
ViewBag.Message = new { Text= ex.Message, CssClass = "alert alert-danger" }
and then use it in this way:
<div class="errormsg #ViewBag.Message.CssClass">
#ViewBag.Message.Text
</div>
If it is a recurrent way to represent a return message in a view, you can create a viewModel class to represent the message and create an helper in Razor to enclosure this render rules in a single place.

Answer 2

I've done the following to do what you're looking for using Tempdata.
#*Display any messages returned from other views*#
<div>
#*Error Message*#
#if (TempData["error"] != null)
{
<div class="alert alert-danger">#TempData["error"]</div>
}
</div>
You will need to check your Viewbag.message for null