示例#1
0
        /// <summary>
        /// This method demonstrates how to undo the changes in Entities level using ObjectContext.
        /// </summary>
        public static void UndoChangesInEntities()
        {
            using (ObjectMySchool school = new ObjectMySchool())
            {
                ObjectDepartment          department = school.ObjectDepartments.FirstOrDefault();
                IQueryable <ObjectCourse> courses    = from c in school.ObjectCourses
                                                       where c.DepartmentID == department.DepartmentID
                                                       select c;

                Console.WriteLine("Before changes:");
                foreach (ObjectCourse course in courses)
                {
                    course.ShowObjectCourse();
                }

                // Change the department and the related course.
                Console.WriteLine("After changes:");
                department.Name += "-Modified";
                foreach (ObjectCourse course in courses)
                {
                    course.Title += "-Modified";
                    course.ShowObjectCourse();
                }

                Console.WriteLine("After Undo Course Entities:");
                // Undo the ObjectCourse type Entities. We will see the changes of the department
                // are not undone.
                school.UndoObjectEntities <ObjectCourse>(school.ObjectCourses);
                foreach (ObjectCourse course in courses)
                {
                    course.ShowObjectCourse();
                }
            }
        }
示例#2
0
        /// <summary>
        /// This method demonstrates how to undo the changes in Entity level using ObjectContext.
        /// </summary>
        public static void UndoChangesInEnity()
        {
            using (ObjectMySchool school = new ObjectMySchool())
            {
                ObjectDepartment          department = school.ObjectDepartments.FirstOrDefault();
                IQueryable <ObjectCourse> courses    = from c in school.ObjectCourses
                                                       where c.DepartmentID == department.DepartmentID
                                                       select c;

                Console.WriteLine("Before changes:");
                foreach (ObjectCourse course in courses)
                {
                    course.ShowObjectCourse();
                }

                // Change the course.
                Console.WriteLine("After changes:");
                foreach (ObjectCourse course in courses)
                {
                    course.Title += "-Modified";
                    course.ShowObjectCourse();
                }

                Console.WriteLine("After Undo the First Course Entity:");
                // Undo one course. You can see only the changes of the first course are undone.
                school.UndoObjectEntity(courses.FirstOrDefault());
                foreach (ObjectCourse course in courses)
                {
                    course.ShowObjectCourse();
                }
            }
        }
示例#3
0
        /// <summary>
        /// This method demonstrates how to undo the changes in Property level using ObjectContext.
        /// </summary>
        public static void UndoChangesInProperty()
        {
            using (ObjectMySchool school = new ObjectMySchool())
            {
                ObjectCourse     course     = school.ObjectCourses.FirstOrDefault();
                ObjectDepartment department = school.ObjectDepartments.FirstOrDefault();
                if (course != null)
                {
                    Console.WriteLine("Before changes:");
                    course.ShowObjectCourse();

                    Console.WriteLine("After changes:");
                    // Change the course Properties.
                    course.Title     += "-Modified";
                    course.Department = department;
                    course.ShowObjectCourse();

                    Console.WriteLine("After Undo Course Entity's Title Property:");
                    // Undo the change in the Entity Property level. UndoObjectEntityProperty
                    // method will undo the Title property of the course, but the change of the
                    // Department Property will not be undone.
                    school.UndoObjectEntityProperty(course, "Title");
                    course.ShowObjectCourse();
                }
            }
        }