public ClaimsIdentity CreateIdentity(User user, string authenticationType)
 {
 ClaimsIdentity _identity = new ClaimsIdentity(DefaultAuthenticationTypes.ApplicationCookie);
 _identity.AddClaim(new Claim(ClaimTypes.Name, user.UserName));
 _identity.AddClaim(new Claim(ClaimTypes.NameIdentifier, user.UserID.ToString()));
 _identity.AddClaim(new Claim("http://schemas.microsoft.com/accesscontrolservice/2010/07/claims/identityprovider", "ASP.NET Identity"));
 _identity.AddClaim(new Claim("DisplayName", user.DisplayName));
 return _identity;
 }

#region 属性
 private IAuthenticationManager AuthenticationManager { get { return HttpContext.GetOwinContext().Authentication; } }
 #endregion

using System.ComponentModel.DataAnnotations;

namespace Ninesky.Web.Areas.Member.Models
{
 /// <summary>
 /// 登录模型
 /// <remarks>
 /// 创建：2014.02.16
 /// </remarks>
 /// </summary>
 public class LoginViewModel
 {
 /// <summary>
 /// 用户名
 /// </summary>
 [Required(ErrorMessage = "必填")]
 [StringLength(20, MinimumLength = 4, ErrorMessage = "{2}到{1}个字符")]
 [Display(Name = "用户名")]
 public string UserName { get; set; }

 /// <summary>
 /// 密码
 /// </summary>
 [Required(ErrorMessage = "必填")]
 [Display(Name = "密码")]
 [StringLength(20, MinimumLength = 6, ErrorMessage = "{2}到{1}个字符")]
 [DataType(DataType.Password)]
 public string Password { get; set; }

 /// <summary>
 /// 记住我
 /// </summary>
 [Display(Name = "记住我")]
 public bool RememberMe { get; set; }
 }
}

/// <summary>
 /// 用户登录
 /// </summary>
 /// <param name="returnUrl">返回Url</param>
 /// <returns></returns>
 public ActionResult Login(string returnUrl)
 {
 return View();
 }

@model Ninesky.Web.Areas.Member.Models.LoginViewModel

@{
 ViewBag.Title = "会员登录";
}

@using (Html.BeginForm()) 
{
 @Html.AntiForgeryToken()
 
 <div class="form-horizontal">
 <h4>会员登录</h4>
 <hr />
 @Html.ValidationSummary(true)

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

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

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

 <div class="form-group">
 <div class="col-md-offset-2 col-md-10">
 <input type="submit" value="登录" class="btn btn-default" />
 </div>
 </div>
 </div>
}

@section Scripts {
 @Scripts.Render("~/bundles/jqueryval")
}

[ValidateAntiForgeryToken]
 [HttpPost]
 public ActionResult Login(LoginViewModel loginViewModel)
 {
 if(ModelState.IsValid)
 {
 var _user = userService.Find(loginViewModel.UserName);
 if (_user == null) ModelState.AddModelError("UserName", "用户名不存在");
 else if (_user.Password == Common.Security.Sha256(loginViewModel.Password))
 {
 var _identity = userService.CreateIdentity(_user, DefaultAuthenticationTypes.ApplicationCookie);
 AuthenticationManager.SignOut(DefaultAuthenticationTypes.ApplicationCookie);
 AuthenticationManager.SignIn(new AuthenticationProperties() { IsPersistent = loginViewModel.RememberMe }, _identity);
 return RedirectToAction("Index", "Home");
 }
 else ModelState.AddModelError("Password", "密码错误");
 }
 return View();
 }

/// <summary>
 /// 登出
 /// </summary>
 /// <returns></returns>
 public ActionResult Logout()
 {
 AuthenticationManager.SignOut(DefaultAuthenticationTypes.ApplicationCookie);
 return Redirect(Url.Content("~/"));
 }