W widoku wyświetla mi lista użytkowników, tylko jak to teraz powiązać żeby się zapisało.
Mam taki model:

using System.Web;

namespace WebManager.Models
{
    public class Task
    {
        public int TaskId { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
        public DateTime DateOfStart { get; set; }
        public DateTime DateOfEnd { get; set; }

        public int ProjectId { get; set; }
        public virtual Project Project { get; set; }

        public virtual ICollection<ApplicationUser> ApplicationUsers { get; set; }

        public Task()
        {
            ApplicationUsers = new List<ApplicationUser>();
        }
    }
}
```csharp
 // GET: Tasks/Create
        public ActionResult Create()
        {
            var users = db.Users.ToList();
            ViewBag.Categories = new MultiSelectList(users, "Email", "Email");
            ViewBag.ProjectId = new SelectList(db.Projects, "ProjectId", "Name");
            return View();
        }

        // POST: Tasks/Create
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "TaskId,Name,Description,DateOfStart,DateOfEnd,ProjectId, users")] Task task)
        {
            if (ModelState.IsValid)
            {
                db.Tasks.Add(task);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            ViewBag.ProjectId = new SelectList(db.Projects, "ProjectId", "Name", task.ProjectId);
            return View(task);
        }
@model WebManager.Models.Task

@{
    ViewBag.Title = "Create";
}

<h2>Create</h2>

@using (Html.BeginForm()) 
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <h4>Task</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.Description, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Description, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Description, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.DateOfStart, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.DateOfStart, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.DateOfStart, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.DateOfEnd, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.DateOfEnd, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.DateOfEnd, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.ProjectId, "ProjectId", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownList("ProjectId", null, htmlAttributes: new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.ProjectId, "", new { @class = "text-danger" })
            </div>
        </div>

        @Html.ListBox("Email", (MultiSelectList)ViewBag.Categories)

        <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")
}
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.EntityFramework;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;
using System.Web;

namespace WebManager.Models
{
    // You can add profile data for the user by adding more properties to your ApplicationUser class, please visit http://go.microsoft.com/fwlink/?LinkID=317594 to learn more.
    public class ApplicationUser : IdentityUser
    {
        public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager)
        {
            // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
            var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
            // Add custom user claims here
            return userIdentity;
        }

        public ICollection<Task> Tasks { get; set; }

        public ApplicationUser()
        {
            Tasks = new List<Task>();
        }
    }
}