标识错误: 值不能为空.r参数名称: 管理器

Question

我使用 ASP.NET 身份，当用户想要注册时收到此错误：

值不能为空。\r参数名称： 管理器。

这是我的注册操作代码：

public virtual ActionResult Register(string nm, string em, string ps)
    {
        var redirectUrlPanel = new UrlHelper(Request.RequestContext).Action("Index", "HomeUsers", new { area = "Users" });
        var redirectUrlAuction = new UrlHelper(Request.RequestContext).Action("Auction", "Default", new { area = "" });
        if (ModelState.IsValid)
        {
            try
            {
                var user = new Q_Users();
                user.UserName = nm;
                user.Email = em;
                user.SecurityStamp = Guid.NewGuid().ToString();
                var adminresult = UserManager.Create(user, ps);
                //Add User Admin to Role Admin
                if (adminresult.Succeeded)
                {
                    //Find Role Admin
                    var role = RoleManager.FindByName("Admin");
                    var result = UserManager.AddToRole(user.Id, role.Name);
                    if (result.Succeeded)
                    {
                        return Json(new { OK = "1", UrlPanel = redirectUrlPanel, UrlAuction = redirectUrlAuction });
                    }
                }
                else
                {
                    return Json(new { OK = "0", UrlPanel = redirectUrlPanel, UrlAuction = redirectUrlAuction });
                }
            }
            catch (Exception ex) { }
            return Json(new { OK = "0", UrlPanel = redirectUrlPanel, UrlAuction = redirectUrlAuction });
        }
        else
        {
            return Json(new { OK = "0", UrlPanel = redirectUrlPanel, UrlAuction = redirectUrlAuction });
        }
    }

而这一行中的错误：var adminresult = UserManager.Create(user, ps);

Answer 1

您收到错误，因为角色管理器未初始化

要解决此问题，请按照以下步骤操作

1. 在Models文件夹的IdentityModels.cs文件中，将下面的类添加到Models namespace。

     public class ApplicationRole : IdentityRole
     {
           public ApplicationRole() : base() { }
           public ApplicationRole(string name) : base(name) { }
     }
   

2. 在App_Start文件夹中IdentityConfig.cs文件中，添加下面的类

   public class ApplicationRoleManager : RoleManager<ApplicationRole>
   {
       public ApplicationRoleManager(IRoleStore<ApplicationRole, string> roleStore)
           : base(roleStore)
       {
       }
       public static ApplicationRoleManager Create(IdentityFactoryOptions<ApplicationRoleManager> options, IOwinContext context)
       {
           return new ApplicationRoleManager(new RoleStore<ApplicationRole>(context.Get<ApplicationDbContext>()));
       }
   }
   

3. 转到App_Start文件夹中Startup.Auth.cs文件，并将以下代码添加到ConfigureAuth方法。

   app.CreatePerOwinContext<ApplicationRoleManager>(ApplicationRoleManager.Create);
   

在此之后，您应该停止收到错误。

希望这有帮助。