模拟对同一实体的 2 个或多个 DBContext 调用失败

Question

我有一个使用 Entity Framework v6.0 和员工表的 MVC ASP.Net 应用程序。我们使用 Code First 方法和标准 Create (CRUD) 方法，该方法具有对现有员工的 EF 查找以及对员工 CreatedBy/ModifiedBy 字段的 EF 查找。尝试为两者（EF 对象存根）创建模拟失败。[HttpPost][ValidateAntiForgeryToken]public ActionResult Create([Bind(Include = "EmployeeID,TeamID,EmployeeADID,FirstName,MiddleName,LastName,EmailAddress,IsAdministrator,IsDeleted")] Employee employee){    if (ModelState.IsValid)    {        //Only unique employee IDs        var existingEmployee = db.Employees.FirstOrDefault(o => o.EmployeeADID == employee.EmployeeADID);        if(existingEmployee != null)        {            ViewBag.Error = "Employee ID must be unique, this employee (" + existingEmployee.FullName + ") already exists in the system.";            ViewBag.TeamID = new SelectList(db.Teams, "TeamID", "Name", employee.TeamID);            return View(existingEmployee);        }        SetAuditFields(employee);        db.Employees.Add(employee);        db.SaveChanges();        return RedirectToAction("Index");    }        ViewBag.TeamID = new SelectList(db.Teams, "TeamID", "Name", employee.TeamID);    return View(employee);}问题是SetAuditFields调用，我需要为编辑操作模拟db.Employees.AsNoTracking AsNoTracking。private void SetAuditFields(Employee employee, bool onlyModified = false){    char sep = '\\';    string pID = User.Identity.Name.Split(sep)[1].ToUpper();    var users = db.Employees.AsNoTracking().Where(c => c.EmployeeADID == pID || c.EmployeeID == employee.EmployeeID).ToList();    var currentUser = users.FirstOrDefault(u => u.EmployeeADID == pID);那么我如何db.Employees.AsNoTracking在最初模拟之后模拟db.Employees呢？下面代码中注释掉的这两行不起作用并失败：“成员 'IQueryable.Provider' 尚未在类型 'DbSet 1Proxy' which inherits from 'DbSet1'上实现我也尝试过，mockContext.SetupSequence但我需要在打开和关闭 AsNoTracking 之间进行交换。当然一定有我遗漏的东西吗？

Answer 1

我最终根据https://stackoverflow.com/a/14368486/495455使用计数器创建了一系列模拟

int callCounter = 1;

mockContext.Setup(m => m.Employees)

    .Returns(() =>

    {

        if (callCounter == 1)

        {

            callCounter++;

            return employeeToEditMockCU;

        }

        else

        {

            return employeeMockCU;

        }

    });

在第一次模拟之后，使用 SetupSequence 进行模拟对我不起作用。db.Employee 在第一次调用后变为空。所以我不使用SetupSequence：

mockContext.SetupSequence(x => x.Employees)

.Returns(employeeToEditMockCU)

.Returns(employeeMockCU);

为了解决这个问题，AsNoTracking()我最终获取了要更新的记录并在不使用的情况下保存它EntityState.Modified：

EF Update using EntityState.Modified