Question

我需要检索特定角色的所有用户，我认为这应该是直截了当的，但是，这就是问题所在。

ApplicationUser的角色导航属性不是角色列表（IdentityRole），而是（IdentityUserroles）的集合，用于链接用户和角色的中间表。所以，这是我的代码，但它不起作用。

[HttpPost]
[Authorize(Roles = "Admin, Recepcionista, Orientador")]
public ActionResult SearchResults(SearchCriteriaViewModel criteria)
{


    List<SearchResultViewModel> results = new List<SearchResultViewModel>();
    var clients = new List<ApplicationUser>();

    using (var context = new ApplicationDbContext())
    {
        IdentityUserRole role = new IdentityUserRole();
        var tempRole = (from _role in context.Roles
                        where _role.Name == "client"
                        select _role).FirstOrDefault();
        role.Role = tempRole;

        clients = (from client in context.Users
                   where client.Email.Contains(criteria.SearchCriteria)
                   || client.FirstName.Contains(criteria.SearchCriteria)
                   || client.MiddleName.Contains(criteria.SearchCriteria)
                   || client.LastName.Contains(criteria.SearchCriteria)
                   || client.SecondLastName.Contains(criteria.SearchCriteria)
                   || client.UserName.Contains(criteria.SearchCriteria)
                   && client.Roles.Contains(role)
                   select client).ToList();


    }

    foreach (var client in clients)
    {
        results.Add(new SearchResultViewModel()
        {
            Email = client.Email,
            FirstName = client.FirstName,
            MiddleName = client.MiddleName,
            LastName = client.LastName,
            SecondLastName = client.SecondLastName,
            UserName = client.UserName
        });
    }

    SearchClientViewModel model = new SearchClientViewModel();
    model.SearchResults = results;

    return View("Index", model);

}

Linq抛出以下异常

发生了'System.NotSupportedException'类型的异常   mscorlib.dll但未在用户代码中处理

其他信息：无法创建类型的常量值   'Microsoft.AspNet.Identity.EntityFramework.IdentityUserRole'。只要   在此上下文中支持原始类型或枚举类型。

如何做到这一点，为什么导航属性不是角色的集合，这可能是我们需要报告的错误吗？

Answer 1

错误信息非常明确：您无法在收集非原始对象时调用Contains。

请尝试以下操作：

    clients = (from client in context.Users
               where client.Email.Contains(criteria.SearchCriteria)
               || client.FirstName.Contains(criteria.SearchCriteria)
               || client.MiddleName.Contains(criteria.SearchCriteria)
               || client.LastName.Contains(criteria.SearchCriteria)
               || client.SecondLastName.Contains(criteria.SearchCriteria)
               || client.UserName.Contains(criteria.SearchCriteria)
               && client.Roles.Select(r => r.Name).Contains("client")
               select client).ToList();

Answer 2

我非常确定Identity Framework中有一个API可以这样做。但是对于您的例外情况，请尝试：

&& client.Roles.Count(r => r.Name == "client") > 0

如何通过ASPnet身份中的Linq检索具有特定角色的用户

2 个答案: