附加类型“UniversalReviewSystem.Models.ApplicationUser”的实体失败，因为相同类型的其他实体已具有相同的主键值。在使用 "Attach" 方法或者将实体的状态设置为 "Unchanged" 或 "Modified" 时如果图形中的任何实体具有冲突键值

在使用asp.net Identity2 的 UserManager RoleManager 时，同时还有其他仓储类型接口，能实现用户扩展信息的修改，用户注册没有问题。当修改用户信息时，出现了如下异常。

 

控制器代码：

public class AccountController : Controller
{
private IDepartmentService _departmentService;

public AccountController(IDepartmentService departmentService)
{
_departmentService = departmentService;

}

private ApplicationUserManager _userManager;

public AccountController(ApplicationUserManager userManager, ApplicationSignInManager signInManager, ApplicationRoleManager roleManager, IDepartmentService departmentService)
{
UserManager = userManager;
SignInManager = signInManager;
RoleManager = roleManager;
_departmentService = departmentService;
}

public ApplicationUserManager UserManager
{
get
{
//return _userManager ?? HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();

return _userManager ?? new ApplicationUserManager(new UserStore<ApplicationUser>(ContextFactory.GetCurrentContext()));
}
private set
{
_userManager = value;
}
}

private ApplicationRoleManager _roleManager;
public ApplicationRoleManager RoleManager
{
get
{
//return _roleManager ?? HttpContext.GetOwinContext().Get<ApplicationRoleManager>();
return _roleManager ?? new ApplicationRoleManager(new RoleStore<ApplicationRole>(ContextFactory.GetCurrentContext()));
}
set
{
_roleManager = value;
}
}

///创建用户不会产生异常。

// GET: /Account/Create
//[Authorize(Roles="SuperAdmin")]
public async Task<ActionResult> Create() //由原Register 方法修改成Create方法
{
ViewBag.RoleID = new SelectList(await RoleManager.Roles.ToListAsync(), "Name", "RoleRealName");
ViewBag.DepartmentID = new SelectList(await _departmentService.FindAll().ToListAsync(), "DepartmentID", "DepartmentName");
// RegisterViewModel registerViewModel = new RegisterViewModel(); //此处可以初始化一个实例，为视图返回一个一些默认值的对象。
return View();
}

//
// POST: /Account/Create
[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Create(RegisterViewModel model, params string[] selectedRoles)//可变数组参数。 模型绑定自动完成，给selectedRoles 可变参数数组传入参数。
{
if (ModelState.IsValid)
{
var user = new ApplicationUser { UserName = model.UserName, Email = model.Email,RealName=model.RealName, Gender=model.Gender,Birthday=model.Birthday,ProfessionalTitle=model.ProfessionalTitle,InCollege=model.InCollege,DepartmentID=model.DepartmentID};
var userResult = await UserManager.CreateAsync(user, model.Password);//添加用户//在数据库中创建了这个用户，那么就生成了UserID 了。

//给用户添加角色
if (userResult.Succeeded)
{
// await SignInManager.SignInAsync(user, isPersistent:false, rememberBrowser:false);

// 有关如何启用帐户确认和密码重置的详细信息，请访问 http://go.microsoft.com/fwlink/?LinkID=320771
// 发送包含此链接的电子邮件
// string code = await UserManager.GenerateEmailConfirmationTokenAsync(user.Id);
// var callbackUrl = Url.Action("ConfirmEmail", "Account", new { userId = user.Id, code = code }, protocol: Request.Url.Scheme);
// await UserManager.SendEmailAsync(user.Id, "确认你的帐户", "请通过单击 <a href=\"" + callbackUrl + "\">這裏</a>来确认你的帐户");

if (selectedRoles != null)
{
var result = await UserManager.AddToRolesAsync(user.Id, selectedRoles);
if (!result.Succeeded)
{
ModelState.AddModelError("", result.Errors.First());
ViewBag.RoleID = new SelectList(await RoleManager.Roles.ToListAsync(), "Name", "RoleRealName");
ViewBag.DepartmentID = new SelectList(await _departmentService.FindAll().ToListAsync(), "DepartmentID", "DepartmentName");
return View(model);

}
}

}

else
{
ModelState.AddModelError("",userResult.Errors.First());
ViewBag.RoleID = new SelectList(await RoleManager.Roles.ToListAsync(), "Name", "RoleRealName");
ViewBag.DepartmentID = new SelectList(await _departmentService.FindAll().ToListAsync(), "DepartmentID", "DepartmentName");
return View(model);
}

return RedirectToAction("Index"); //如果用户添加成功，角色创建成功就返回Index.2、如果用户添加成功，但没有选中角色，也返回Index.

}
// 如果我们进行到这一步时某个地方出错，则重新显示表单

ViewBag.RoleID = new SelectList(await RoleManager.Roles.ToListAsync(), "Name", "RoleRealName");
ViewBag.DepartmentID = new SelectList(await _departmentService.FindAll().ToListAsync(), "DepartmentID", "DepartmentName");

return View(model);
}

//Get Account/EditUser 系统管理员修改其他人的信息
public async Task<ActionResult> EditUser(string Id)
{
if (string.IsNullOrEmpty(Id))
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest); //HttpStatusCode.BadRequest 在System.Net 命名空间下面。
}

var _user = await UserManager.FindByIdAsync(Id);
if (_user == null)
{
return HttpNotFound();
}

var userRoles = await UserManager.GetRolesAsync(_user.Id);

var editUser = new EditUserViewModel
{
Id = _user.Id,
UserName = _user.UserName,
Email = _user.Email,
RealName = _user.RealName,
Gender = _user.Gender,
Birthday = _user.Birthday,
InCollege = _user.InCollege,
ProfessionalTitle = _user.ProfessionalTitle,
RolesList = RoleManager.Roles.ToList().Select(x => new SelectListItem() //建立一个投影，如果角色中包含当前用户的角色，就选中此角色。
{
Text =x.RoleRealName + "-"+ x.Description,
Value =x.Name,
Selected =userRoles.Contains(x.Name)
})

};

ViewBag.DepartmentList = new SelectList(_departmentService.FindAll().OrderBy(d => d.DepartmentName), "DepartmentID", "DepartmentName",_user.DepartmentID);

return View(editUser);

}
/// <summary>
/// 管理员编辑其他用户的信息
/// </summary>
/// <param name="user"></param>
/// <param name="selectedRoles"></param>
/// <returns></returns>
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> EditUser([Bind(Include = "Id,UserName,Email,RealName,Gender,Birthday,DepartmentID,InCollege,ProfessionalTitle")] EditUserViewModel user, params string[] selectedRoles)
{

if (ModelState.IsValid)
{
//var _user = await UserManager.Users.AsNoTracking().SingleOrDefaultAsync(x => x.Id == user.Id);
var _user = await UserManager.FindByIdAsync(user.Id);
if (_user == null)
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);

_user.UserName = user.UserName;
_user.Email = user.Email;
_user.RealName = user.RealName;
_user.Gender = user.Gender;
_user.Birthday =user.Birthday;
_user.DepartmentID = user.DepartmentID;
_user.InCollege = user.InCollege;
_user.ProfessionalTitle = user.ProfessionalTitle;

var userRoles = await UserManager.GetRolesAsync(_user.Id);
selectedRoles = selectedRoles ?? new string[] { };

var result = await UserManager.AddToRolesAsync(user.Id, selectedRoles.Except(userRoles).ToArray<string>());
if (!result.Succeeded)
{
ModelState.AddModelError("", result.Errors.First());
ViewBag.DepartmentList = new SelectList(_departmentService.FindAll().OrderBy(d => d.DepartmentName), "DepartmentID", "DepartmentName", _user.DepartmentID);
return View(user);
}

result = await UserManager.RemoveFromRolesAsync(user.Id, userRoles.Except(selectedRoles).ToArray<string>());
if (!result.Succeeded)
{
ModelState.AddModelError("", result.Errors.First());
ViewBag.DepartmentList = new SelectList(_departmentService.FindAll().OrderBy(d => d.DepartmentName), "DepartmentID", "DepartmentName", _user.DepartmentID);
return View(user);
}

await UserManager.UpdateAsync(_user); //异步更新用户信息  执行到此处出现 了   “附加类型“UniversalReviewSystem.Models.ApplicationUser”的实体失败，因为相同类型的其他实体已具有相同的主键值。”的异常。

return RedirectToAction("Index");
}

ModelState.AddModelError("", "绑定失败");
ViewBag.DepartmentList = new SelectList(_departmentService.FindAll().OrderBy(d => d.DepartmentName), "DepartmentID", "DepartmentName", user.DepartmentID);
return View(user);

}

另外，还定义一个静态的工厂类，用于产生数据库上下文。

public static class ContextFactory //静态类不能被实例化，只能有静态成员。
{
public static UniversalReviewSystemDbContext GetCurrentContext()
{
UniversalReviewSystemDbContext context = CallContext.GetData("UniversalReviewSystemContext") as UniversalReviewSystemDbContext;
if (context == null)
{
context = new UniversalReviewSystemDbContext();
CallContext.SetData("UniversalReviewSystemContext", context);
}

return context;

}

}

出现异常的原因，可能是UserManager、RoleManager使用了不同的数据库上下文。 ContextFactory 使用CallContext 并不能保证数据库上下文一致。 把数据库上下文更改一下就行了。但同时增加了 userManager 用户的验证逻辑。

在UserManager 和RoleManager 的属性中，

恢复默认的

get
{
return _userManager ?? HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();

}

get
{
return _roleManager ?? HttpContext.GetOwinContext().Get<ApplicationRoleManager>();

}

也可以在控制器中 为UserManager,RoleManager 使用同一数据库上下文对象。

UniversalReviewSystemDbContext db =ContextFactory.GetCurrentContext();

return _userManager ?? new ApplicationUserManager(new UserStore<ApplicationUser>(db));

return  _roleManager ??  new ApplicationRoleManager(new RoleStore<ApplicationRole>(ContextFactory.GetCurrentContext()));