C# 角色''；找不到

我正在MVC4应用程序中添加新角色。。。但每次它都会出现这个错误

这是我的注册方法

 //
        // POST: /Account/Register
         [AllowAnonymous]
        [HttpPost]
        public ActionResult Register(RegisterModel model)
        {
            if (ModelState.IsValid)
            {
                object x = Membership.GetUser(model.UserName);

                if (Membership.GetUser(model.UserName) == null)
                {
                    // Attempt to register the user
                    MembershipCreateStatus createStatus;
                    Membership.CreateUser(model.UserName, model.Password, model.Email, null, null, true, null,
                        out createStatus);

                    if (createStatus == MembershipCreateStatus.Success)
                    {


                        Roles.AddUserToRole(model.UserName, model.Role);

 //model.Role is the DropDown Selected Text.. its value is 'Admin'

                        FormsAuthentication.SetAuthCookie(model.UserName,   
   false /* createPersistentCookie */);
                        return RedirectToAction("Index", "EUT");
                    }
                    else
                    {
                        ModelState.AddModelError("",  
     ErrorCodeToString(createStatus));
                    }

                }
                else
                {

                    ModelState.AddModelError("", "User Already exists");
                }
            }

            // If we got this far, something failed, redisplay form
            return View(model);
        }

在我的网页配置中

 <membership>
      <providers>
        <clear/>
        <add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices"
             enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false"
             maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10"
             applicationName="/" />
      </providers>
    </membership>

    <profile>
      <providers>
        <clear/>
        <add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="ApplicationServices" applicationName="/" />
      </providers>
    </profile>

    <roleManager enabled="true"  defaultProvider="AspNetSqlRoleProvider"
                                    cacheRolesInCookie="true"
                                    cookieName=".myroles"
                                    cookieTimeout="30"
                                    cookieSlidingExpiration="true"
                                    cookieProtection="All">
      <providers>
        <clear/>
        <add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/" />
        <add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/" />
      </providers>
    </roleManager>

在中，尝试将选定值与模型属性绑定…但仍不起作用

任何建议都会很有帮助
您可以检查该角色是否存在，如果不喜欢，则添加该角色：

var adminRoleExists = Roles.RoleExists(AppRoles.Admin.ToString());
if (!adminRoleExists)
{
    Roles.CreateRole(AppRoles.Admin.ToString());
}

Roles.AddUserToRole（model.UserName，model.Role）
model.Role

此时是什么？model.Role是下拉选择的文本它的值是什么，而不是它的值是什么。您是否双重确认在调试器上的

model.Role

中设置了该值…model.UserName==“MyName”和model.Role=“admin”（DDL Selected Text）显示