[Architect] Abp 原理解析(3) DynamicFilters

本節目錄

• 介紹
• 定義Filter
• 設置Filter

這是Abp中多租戶、軟刪除、激活\禁用等如此方便的原因

Install-Package EntityFramework.DynamicFilters

定義數據

    class DemoDb : DbContext
    {
        public DemoDb() : base("Default")
        {
        }

        public IDbSet<Blog> Blogs { get; set; }
    }

    interface ISoftDelete
    {
        bool IsDeleted { get; set; }
    }

    class Blog : ISoftDelete
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public bool IsDeleted { get; set; }
    }

初始化數據

        static void Main(string[] args)
        {
            using (var db = new DemoDb())
            {
                for (int i = 0; i < 5; i++)
                {
                    db.Blogs.Add(new Blog { Name = i.ToString() });
                }

                for (int i = 0; i < 5; i++)
                {
                    db.Blogs.Add(new Blog { Name = i.ToString(), IsDeleted = true });
                }
                db.SaveChanges();
            }
            Console.WriteLine("Done");

            Console.ReadLine();
        }

查詢數據

        private static void Query()
        {
            using (var db = new DemoDb())
            {
                Console.WriteLine(db.Blogs.Count());
            }
        }

定義Filter

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            //以下幾種效果均一樣
            modelBuilder.Filter("IsDeleted", (ISoftDelete entity) => entity.IsDeleted, false);

            //modelBuilder.Filter("IsDeleted", (ISoftDelete entity) => entity.IsDeleted == false);

            //modelBuilder.Filter("IsDeleted", (Blog entity) => entity.IsDeleted, () =>
            //{
            //    //todo other
            //    return false;
            //});

            //多參數情況
            modelBuilder.Filter("BlogFilter",
                    (Blog b, int id, bool isDeleted) => (b.Id == id) && (b.IsDeleted == isDeleted),
                    () => 1,
                    () => false);
        }

設置Filter

修改參數值

        private static void Query()
        {
            using (var db = new DemoDb())
            {
                db.SetFilterScopedParameterValue("IsDeleted", true);
                db.SetFilterScopedParameterValue("BlogFilter", "id", 2);
                Console.WriteLine(db.Blogs.Count());
            }
        }

啟用/禁用過濾

禁用代碼:

context.DisableFilter("IsDeleted");

context.DisableAllFilter();

modelBuilder.DisableFilterGlobally("IsDeleted");

啟用代碼:

context.EnableFilter();

context.EnableAllFilter();

參考:

https://github.com/jcachat/EntityFramework.DynamicFilters

本文地址:http://www.cnblogs.com/neverc/p/5258184.html