BeginCollectionItem Postback with Duplicate GUID | C# Online Compiler

BeginCollectionItem Postback with Duplicate GUID by KyleMit

using System;
using System.ComponentModel.DataAnnotations;

namespace HelloWorldMvcApp
{

	
	public class Person {
		public int ID {get;set;}
		public string Name { get; set;}
	}
}

Model

​x
 
using System;
using System.ComponentModel.DataAnnotations;
​
namespace HelloWorldMvcApp
{
​
    
    public class Person {
        public int ID {get;set;}
        public string Name { get; set;}
    }
}

@using HtmlHelpers.BeginCollectionItem
@model IEnumerable<HelloWorldMvcApp.Person>


@{
	Layout = null;
}

<!DOCTYPE html>
<!-- template from http://getbootstrap.com/getting-started -->

<html lang="en">
	<head>
		<meta charset="utf-8">
		<meta http-equiv="X-UA-Compatible" content="IE=edge">
		<meta name="viewport" content="width=device-width, initial-scale=1">
		<title>Bootstrap 101 Template</title>

		<!-- CSS Includes -->
		<link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">

	</head>
	
	<body>
		<div class="container">
			<div class="col-md-6 col-md-offset-3">
				<h1>Hello Stranger</h1>
	
				@using (Html.BeginForm())
				{
					<div class="people">
						
						@for (int i = 0; i < Model.Count(); i++ )
						{
										   
							 <div class="person">
								 
								 @using (Html.BeginCollectionItem())
								  {
											
									  <div class="form-group">
										  @Html.DisplayNameFor(model => model[i].ID)
										  @Html.DisplayFor(model => model[i].ID, new {@class="form-control"}) 
										  @Html.HiddenFor(model => model[i].ID)
									  </div>	
									  <div class="form-group">
										  @Html.LabelFor(model => model[i].Name)
										  @Html.TextBoxFor(model => model[i].Name, new {@class="form-control"}) 
										  @Html.ValidationMessageFor(model => model[i].Name)
									  </div>	
											
								  }
							 </div>	
						 }
									
					</div>		
								
					<button type="button" class="btn btn-success submit">Add</button>
				}
	
				<br/><br/>
				
			</div>
		</div>

		<!-- JS includes -->
		<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
		<script src="//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>
	
		<script src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/jquery.validate.min.js"></script>
		<script src="//ajax.aspnetcdn.com/ajax/mvc/4.0/jquery.validate.unobtrusive.min.js"></script>
		
		<script type="text/javascript">

		
			$(function(){

		
				$('.submit').click(function(){
					$data = $("form").serializeArray();
					
					$.ajax({
						url: '@Url.RouteUrl(new{ action="AddPerson", controller="Home"})',
						data: $data,
						type: 'POST',
						success: function(resp) {
							var $resp = $(resp);
							var $per = $resp.find(".person");
							$(".people").append($per);
						}
					});
					
				});
			
			});

		</script>
	</body>
</html>

View

 
@using HtmlHelpers.BeginCollectionItem
@model IEnumerable<HelloWorldMvcApp.Person>
​
​
@{
    Layout = null;
}
​
<!DOCTYPE html>
<!-- template from http://getbootstrap.com/getting-started -->
​
<html lang="en">
    <head>
        <meta charset="utf-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <title>Bootstrap 101 Template</title>
​
        <!-- CSS Includes -->
        <link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">
​
    </head>
    
    <body>
        <div class="container">
            <div class="col-md-6 col-md-offset-3">
                <h1>Hello Stranger</h1>
    
                @using (Html.BeginForm())
                {
                    <div class="people">
                        
                        @for (int i = 0; i < Model.Count(); i++ )
                        {
                                           
                             <div class="person">
                                 
                                 @using (Html.BeginCollectionItem())
                                  {
                                            
                                      <div class="form-group">
                                          @Html.DisplayNameFor(model => model[i].ID)
                                          @Html.DisplayFor(model => model[i].ID, new {@class="form-control"}) 
                                          @Html.HiddenFor(model => model[i].ID)
                                      </div>    
                                      <div class="form-group">
                                          @Html.LabelFor(model => model[i].Name)
                                          @Html.TextBoxFor(model => model[i].Name, new {@class="form-control"}) 
                                          @Html.ValidationMessageFor(model => model[i].Name)
                                      </div>    
                                            
                                  }
                             </div> 
                         }
                                    
                    </div>      
                                
                    <button type="button" class="btn btn-success submit">Add</button>
                }
    
                <br/><br/>
                
            </div>
        </div>
​
        <!-- JS includes -->
        <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
        <script src="//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>
    
        <script src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/jquery.validate.min.js"></script>
        <script src="//ajax.aspnetcdn.com/ajax/mvc/4.0/jquery.validate.unobtrusive.min.js"></script>
        
        <script type="text/javascript">
​
        
            $(function(){
​
        
                $('.submit').click(function(){
                    $data = $("form").serializeArray();
                    
                    $.ajax({
                        url: '@Url.RouteUrl(new{ action="AddPerson", controller="Home"})',
                        data: $data,
                        type: 'POST',
                        success: function(resp) {
                            var $resp = $(resp);
                            var $per = $resp.find(".person");
                            $(".people").append($per);
                        }
                    });
                    
                });
            
            });
​
        </script>
    </body>
</html>
​

using System;
using System.Web.Mvc;
using System.Collections.Generic;

namespace HelloWorldMvcApp
{
	public class HomeController : Controller
	{
		[HttpGet]
		public ActionResult Index()
		{
			
			List<Person> vm = new List<Person> {
				new Person() { ID = 1 , Name="Bob" },
				new Person() { ID = 2 , Name="Sue" },
				new Person() { ID = 3 , Name="Elm" },					
			};
			return View(vm);
		}


		[HttpPost]
		public ActionResult AddPerson(List<Person> vm)
		{	

			int maxId = 0; // vm.Max(p=> p.ID);
			foreach (Person per in vm) {
				if (per.ID > maxId) maxId = per.ID;
			}
			
			Person person = new Person { ID = maxId + 1, Name="" };
			
			return View("Index", person);
		}


	}
	
	
}

Controller

 
using System;
using System.Web.Mvc;
using System.Collections.Generic;
​
namespace HelloWorldMvcApp
{
    public class HomeController : Controller
    {
        [HttpGet]
        public ActionResult Index()
        {
            
            List<Person> vm = new List<Person> {
                new Person() { ID = 1 , Name="Bob" },
                new Person() { ID = 2 , Name="Sue" },
                new Person() { ID = 3 , Name="Elm" },                   
            };
            return View(vm);
        }
​
​
        [HttpPost]
        public ActionResult AddPerson(List<Person> vm)
        {   
​
            int maxId = 0; // vm.Max(p=> p.ID);
            foreach (Person per in vm) {
                if (per.ID > maxId) maxId = per.ID;
            }
            
            Person person = new Person { ID = maxId + 1, Name="" };
            
            return View("Index", person);
        }
​
​
    }
    
    
}

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