Question

this is my first time ever posting a question and I am kind of new to Visual Studio 2010. I have a web application (for a school assignment) that allows you to create a “news item” that will be displayed on the front page. I have done everything in my assignment except I can’t for the life of me figure out how to have valiadation on my form whenever a textbox on the form is left empty. I have been looking everywhere and have followed a few tutorials but still can’t get it to work with my particular case. I went to my database in the visual designer, right clicked it and clicked “view code” and placed this in there:

using System.ComponentModel.DataAnnotations;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace NewsDisplay
{
  partial class NewsItemDataContext
  {
  }

  [MetadataType(typeof(NewsItem_Validation))]
  public partial class NewsItem
  {

  }

  public class NewsItem_Validation
  {
     [Required(ErrorMessage = "Title is Required")]
     public string Title { get; set; }
  }
}

And then my create function is in my Homecontroller and looks like this:

    [HttpPost]
    public ActionResult Create(FormCollection formData)
    {
        NewsItem n = new NewsItem();
        if (ModelState.IsValid)
        {
            TryUpdateModel(n);
            NewsItemRepository repository = new NewsItemRepository();
            repository.AddNewsItem(n);
            return RedirectToAction("index");
        }
        else
        {
            return View(formData);
        }

    }

At first I would get thrown an exception at UpdateModel, but then I found that using TryUpdateModel works. Now I get thrown an exception at my .aspx code that controls the home page because the Title of the news item cannot be blank. Here is my index.aspx page with a comment at where I get the exception:

<%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<IEnumerable<NewsDisplay.NewsItem>>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Home Page
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<h2>Newest Stories</h2>
<% foreach (var item in Model) { %>
    <table class="center">
        <thead>
            <tr>
                <td>
                    <%= Html.ActionLink( item.Title, "Edit", new { id=item.NewsItemID } ) %> //this is where I get thrown the exception
                </td>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td id="topRow">
                    <%: item.Date %>
                </td>
            </tr>
            <tr>
                <td id="bottomRow">
                    <%: item.Details %>
                </td>
            </tr>
        </tbody>
    </table>
<% } %>
</asp:Content>

Am I even on the right track? I have been looking this up for a while now and I just can’t seem to figure out how to make it work for my personal project. Thanks in advance for any help!

Answer 1

why u dont use validator on control box?
u can use validator and set the control that must be validate and define error message on control

the page never post if data in control not valid

here is example

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
    <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" 
        ControlToValidate="TextBox1" ErrorMessage="Write Error Message Here"></asp:RequiredFieldValidator>

solve your problem?