AutoMapper的使用

在依赖项中右击打开管理Nuget程序包，搜索AutoMapper并安装。

使用AutoMapper将一个对象赋值给另外一个对象

BookDto 实体类对象

    public class BookDto
    {
        public string Title { get; set; }

        public string Author { get; set; }

        public int Status { get; set; }

        public int buyCount { get; set; } = 5;

        public DateTime CreateDate { get; set; } = DateTime.Now;

        public string Remark { get; set; } = "123456789765432";

        public string Test1 { get; set; }

        
    }

BookViewModel 用户显示视图的模型对象

    public class BookViewModel
    {
        public string Title { get; set; }

        public string Author { get; set; }

        public string StatusText { get; set; }

        public string CreateDate { get; set; }

        public int buyCount { get; set; }

        public string Remark { get; set; }

        public string Test1 { get; set; }

        public string BookInfo { get; set; }
    }

得到BookDto的实例对象，需要给BookViewModel

            BookDto book = new BookDto()
            {
                Author = "度边",
                Title = "知行合一王阳明",
                Status = 1
            };

如何将BookDto实例对象的值赋给BookViewModel实例呢？

        /// <summary>
        /// 使用AutoMaper将BookDto实例赋值给BookViewModel实例
        /// </summary>
        /// <param name="book"></param>
        /// <returns></returns>
        public static BookViewModel PrepareBookViewModel(BookDto book)
        {
            var config2 = new MapperConfiguration(
                    cfg => cfg.CreateMap<BookDto, BookViewModel>()
                        .ForMember(d => d.Title, opt => opt.MapFrom(s => s.Title))    //指定字段一一对应
                        .ForMember(d => d.CreateDate, opt => opt.MapFrom(src => src.CreateDate.ToString("yy-MM-dd HH:mm:ss")))//指定字段，并转化指定的格式
                        .ForMember(d => d.buyCount, opt => opt.Condition(src => src.buyCount > 5))//条件赋值
                        .ForMember(d => d.Remark, opt => opt.Ignore())//忽略该字段，不给该字段赋值
                        .ForMember(d => d.Test1, opt => opt.NullSubstitute("空了"))//如果源字段值为空，则赋值为 空了
                        .ForMember(d => d.StatusText, opt =>
                        {
                            opt.MapFrom(s => s.Status == 1 ? "可用" : "不可用");
                        })
                        .ForMember(d => d.BookInfo, opt => opt.MapFrom(src => src.Title + src.CreateDate.ToString("yyyy-MM-dd"))));//可以自己随意组合赋值
            var mapper2 = config2.CreateMapper();
            return mapper2.Map<BookViewModel>(book);

        }