ASP.NET Core Identity UserManager.IsInRole 调用在 2.2 中有效，但在 3.0 中引发 InvalidOperation

Question

我有 2 个使用 ASP.NET Core Identity 的解决方案。一个是 v.2.2，另一个是 3.0。他们调用 UserManager.IsInRole(user, role.Name)。该代码在 v.2.2 中有效，但会引发异常，“InvalidOperationException：已经有一个打开的 DataReader 与此命令关联，必须先关闭它。”在 v.3.0 中。他们都在构建两个用户列表，一个是目标角色的用户，另一个不是目标角色的用户。这个想法是从目标角色中添加或删除用户。

我已经搜索过这里、Microsoft 文档和一些博客，但似乎没有任何东西可以解决我的问题

这是有问题的代码：

    public async Task<IActionResult> OnGetAsync(string id)
    {
        IdentityRole role = await roleManager.FindByIdAsync(id);
        List<FREEIncUser> members = new List<FREEIncUser>();
        List<FREEIncUser> nonMembers = new List<FREEIncUser>();
        foreach (FREEIncUser user in userManager.Users)
        {
            var list = await userManager.IsInRoleAsync(user, role.Name) ? members : nonMembers;
            list.Add(user);
        } // end foreach (FREEIncUser user in userManager.Users)

        RoleUserViewModel = new RoleUserViewModel
        {
            Role = role,
            Members = members,
            NonMembers = nonMembers
        };

        return Page();
    } // end public async Task<IActionResult> OnGetAsync(string id)

以下是一些截图： v.2.2

这给出了：

v.3.0

这会产生一个异常： 处理请求时发生未处理的异常。 InvalidOperationException: 已经有一个打开的 DataReader 与此命令关联，必须先关闭。

Microsoft.Data.SqlClient.SqlCommand+c.b__164_0（任务结果）

Stack Query Cookies Headers Routing 

InvalidOperationException: There is already an open DataReader associated with this Command which must be closed first.
    Microsoft.Data.SqlClient.SqlCommand+<>c.<ExecuteDbDataReaderAsync>b__164_0(Task<SqlDataReader> result)
    System.Threading.Tasks.ContinuationResultTaskFromResultTask<TAntecedentResult, TResult>.InnerInvoke()
    System.Threading.Tasks.Task+<>c.<.cctor>b__274_0(object obj)
    System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, object state)
    System.Threading.Tasks.Task.ExecuteWithThreadLocal(ref Task currentTaskSlot, Thread threadPoolThread)
    Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
    Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
    Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
    Microsoft.EntityFrameworkCore.Query.RelationalShapedQueryCompilingExpressionVisitor+AsyncQueryingEnumerable<T>+AsyncEnumerator.MoveNextAsync()
    System.Runtime.CompilerServices.ValueTaskAwaiter<TResult>.GetResult()
    Microsoft.EntityFrameworkCore.Query.ShapedQueryCompilingExpressionVisitor.SingleOrDefaultAsync<TSource>(IAsyncEnumerable<TSource> asyncEnumerable, CancellationToken cancellationToken)
    Microsoft.EntityFrameworkCore.Query.ShapedQueryCompilingExpressionVisitor.SingleOrDefaultAsync<TSource>(IAsyncEnumerable<TSource> asyncEnumerable, CancellationToken cancellationToken)
    Microsoft.AspNetCore.Identity.EntityFrameworkCore.UserStore<TUser, TRole, TContext, TKey, TUserClaim, TUserRole, TUserLogin, TUserToken, TRoleClaim>.IsInRoleAsync(TUser user, string normalizedRoleName, CancellationToken cancellationToken)
    Microsoft.AspNetCore.Identity.UserManager<TUser>.IsInRoleAsync(TUser user, string role)
    FREEInc.WebUI.Pages.RoleAdmin.ManageUsersModel.OnGetAsync(string id) in ManageUsers.cshtml.cs

                    var list = await userManager.IsInRoleAsync(user, role.Name) ? members : nonMembers;
Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.ExecutorFactory+GenericTaskHandlerMethod.Convert<T>(object taskAsObject)
Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.ExecutorFactory+GenericTaskHandlerMethod.Execute(object receiver, object[] arguments)
Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.PageActionInvoker.InvokeHandlerMethodAsync()
Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.PageActionInvoker.InvokeNextPageFilterAsync()
Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.PageActionInvoker.Rethrow(PageHandlerExecutedContext context)
Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.PageActionInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted)
Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.PageActionInvoker.InvokeInnerFilterAsync()
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)
Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

投掷线是：

var list = await userManager.IsInRoleAsync(user, role.Name) ? members : nonMembers;

我们将不胜感激任何帮助和指导。谢谢。

Answer 1

将此添加到您的连接字符串：MultipleActiveResultSets=True;

Answer 2

试试这个代码

foreach (FREEIncUser user in userManager.Users.ToList())
{
    var list = await userManager.IsInRoleAsync(user, role.Name) ? members : nonMembers;
    list.Add(user);
}

问题是你不能在DbContext 上同时有多个连接，当你在userManager.Users 上有一个 foreach 时，连接是打开的并且记录一个一个地返回，你可以有另一个查询（IsInRole）在同一个DbContext上。

通过将ToList() 添加到userManager.Users，您将获得所有用户并对其进行迭代。