How to use html.ValidationMessageFor

Question

I'm trying to get my view to give me the error message next to the text box if a user enters something invalid (like a string where it's expecting a number). Instead, I'm getting an ugly error page saying validation failed when the user presses submit.

Here is a portion of my view:

@model MembershipTest.ViewModels.AddDriverViewModel  <script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>  @{ Layout = "~/Views/Shared/_Layout.cshtml"; ViewBag.Title = "Add Drivers"; }  @using (Html.BeginForm("AddDriver", "Driver")) { @Html.AntiForgeryToken() @Html.ValidationSummary(true)  <fieldset> <legend>Customer Information</legend>  <table>      <tr>          <td>              @Html.Label("First Name:")              @Html.TextBoxFor(m => m.Driver.F_Name)              @Html.ValidationMessageFor(m => m.Driver.F_Name)          </td>          <td>              @Html.Label("Gender:")               @Html.RadioButtonFor(m => m.isMaleChecked, "true") Male              @Html.RadioButtonFor(m => m.isMaleChecked, "false")Female          </td>      </tr>      <tr>          <td>              @Html.Label("Last Name:")              @Html.TextBoxFor(m => m.Driver.L_Name)              @Html.ValidationMessageFor(m => m.Driver.L_Name)          </td> 

And here is the relevant portion of my model:

[Required] [StringLength(30)] public string F_Name { get; set; }  [Required] [StringLength(30)] public string L_Name { get; set; } 

In the post method of my controller, I make sure to use

if (ModelState.IsValid) 

If the user happened to enter something like 50 characters long in the first name text box, I want an error to be displayed using the Html.ValidationMessageFor() right when they tab out of that text box, so they can see it before they press submit. Am I missing some jquery to make this happen? Maybe some using statement I need to include?

Answer 1

It was silly simple.....I just didn't add the ErrorMessage field as part of the [Required] decorator. For example:

[Required(ErrorMessage = "First name is required")] [StringLength(30, ErrorMessage = "Name can be no larger than 30 characters")] public string F_Name { get; set; }  [Required(ErrorMessage = "Last name is required")] [StringLength(30, ErrorMessage = "Name can be no larger than 30 characters")] public string L_Name { get; set; } 

Now, if a user either doesn't enter anything in the name fields, or enters something over 30 characters, the Post method doesn't get executed and the user gets a little message telling them what's wrong.