[在使用UserManager.IsInRoleAsync（）时出现InvalidOperationException

Question

我正在尝试让所有用户都在我正在编辑的角色中。但是当我加载页面时，它一直在给我InvalidOperationException：当此命令有打开的DataReader时，无法设置MySqlCommand.CommandText；它必须先关闭。

public async Task<IActionResult> EditRole(string id)
       {
            var role = await roleManager.FindByIdAsync(id);
            if(role == null)
            {
                ViewBag.ErrorMessage = $"Role with id = {id} cannot be found";
                return View("NotFound");
            }


            var model = new EditRoleModel
            {
                Id = role.Id,
                RoleName = role.Name
            };

            foreach(var user in userManager.Users)
            {
                var userInRole = await userManager.IsInRoleAsync(user, role.Name);
                if (userInRole)
                {
                    model.Users.Add(user.UserName);
                }
            }
            return View(model);
        }

我在这里遇到错误V

var userInRole = await userManager.IsInRoleAsync(user, role.Name);