本文参考了Taswar Bhatti的博客，他写了《Instant AutoMapper》这本书。遗憾的是，这本电子版书在国内还买不到，也下载不到。也只能从他的有限几篇博文中来窥探一二了。
本文模拟了一个关于订单的应用场景，涉及到的方面包括：
※ 显示所有订单
※ 显示客户信息
※ 显示订单，但不显示view model OrderDto中的集合导航属性
※ 把源中的DateTime类型转换成int类型
※ 把源中的bool类型转换成string类型
※ 把源中的集合导航属性IEnumerable<OrderItems> LineItems转换成目标中的计算数量的string类型
显示所有订单
□ 思路
从数据库获取Domain model,再转换成View model.
View Model的属性，要方便读取。
Domain model的一些属性、方法是ViewModel不需要的，比如复杂属性Customer,计算总额的方法。
□ Domian model
//订单模型，差不多包含以下方面：
//客户：复杂类型
//下单时间
//一个LineItem的集合
//一个计算总价的方法
//等等
public class Order
{
public string OrderNo{get;set;}
public Customer Customer{get;set;}
public DateTime PurchaseDate{get;set;}
public bool ShipToHomeSddress{get;set;}
public Guid InternalId{get;set;}
public IEnumerable<OrderItems> LineItems{get;set;}
public decimal GetTotal()
{
return LineItems == null ? 0 : LineItems.Sum(x => x.GetTotalPrice());
}
}
//LineItems
//名称、价格、数量，计算每个Line的金额=价格*数量
public class OrderItems
{
public decimal Price{get;set;}
public string Name{get;set;}
public int Quantity{get;set;}
public decimal GetTotalPrice()
{
return Price * Quantity;
}
}
public class Customer
{
public string FirstName{get;set;}
public string LastName{get;set;}
public string Bio{get;set;}
public string GetName()
{
return FirstName + ‘ ‘ + LastName;
}
}
□ View model
public class OrderDto
{
public string CustomerName{get;set;} //对应源中复杂属性Customer+Customer的属性，符合惯例
public decimal Total{get;set;} //对应源中GetTotal方法，符合惯例
public string OrderNumber{get;set;} //对应domain model中的OrderNo，需要映射配置
public IEnumerable<OrderItemDto> LineItems{get;set;} //与源中属性保存一致，别忘了OrdeerItemDto需要配置
}
public class OrderItemsDto
{
public string Name{get;set;}
public int Quantity{get;set;}
public decimal Price{get;set;}
}
public class CustomerDto
{
public string Bio{get;set;}
public string Name{get;set;} //与源中的GetName对应
}
□ 控制器
public ActionResult OrderItems()
{
var orders = _repository.GetAll();
Mapper.CreateMap<Order, OrderDto>
.ForMember(dest => dest.OrderNumber, opt => opt.MapFrom(src => src.orderNo));
Mapper.CreateMap<OrderItems, OrderItemsDto>();
var model = Mapper.Map<IEnumerable<Order>, IEnumerable<OrderDto>>(orders);
return View(model);
}
□ 视图
@model IEnumerable<OrderDto>
@foreach(var item in Model)
{
@item.OrderNumber
@item.CustomerName
@item.Total
@foreach(var child in item.LineItems)
{
@string.Format("({0}) {1} - {2}", @child.Quantity, @Child.Name, @Child.Price)<br />
}
}
显示客户信息
□ 思路
假设Domain model Customer的属性Bio有可能是null,如果映射到CustomerDto的Bio属性，也会是null值。
用到了某属性是null的替换方法.NullSubstitute();
□ 控制器
public ActionResult Index()
{
var customers = _repository.GetAll();
AutoMapper.Mapper.CreateMap<Customer, CustomerDto>()
.ForMember(dest => dest.Bio, opt => opt.NullSubstitute("N/A"))
var model = AutoMapper.Mapper.Map<IEnumerable<Customer>, IEnumerable<CustomerDto>>(customers);//集合与集合的映射
return View(model);
}
□ 视图
@model IEnumerable<CustomerDto>
@foreach(var customer in Model)
{
@customer.Name
@Customer.Bio
}
显示订单，但不显示view model OrderDto中的集合导航属性
□ 思路
方法Ignore(),把目标中的某个属性忽略。
□ Domain model
public class Order
{
public string OrderNo { get; set; }
public Customer Customer { get; set; }
public DateTime PurchaseDate { get; set; }
public IEnumerable<OrderItems> LineItems { get; set; }
public bool ShipToHomeAddress { get; set; }
public decimal GetTotal()
{
return LineItems == null ? 0 : LineItems.Sum(x => x.GetTotalPrice());
}
public Guid InternalId { get; set; }
}
public class OrderItems
{
public decimal Price{get;set;}
public string Name{get;set;}
public int Quantity{get;set;}
public decimal GetTotalPrice()
{
return Price * Quantity;
}
}
□ View model
public class OrderDto
{
public string CustomerName { get; set; } //与源model的导航属性的字段对应
public decimal Total { get; set; } //与源model的GetTotal()方法对应
public string OrderNumber { get; set; }
public IEnumerable<OrderItemsDto> LineItems { get; set; }
}
□ 控制器
public ActionResult Index()
{
var orders = _reposiotry.GetAll();
AutoMapper.Mapper.CreateMap<Order, OrderDto>()
.ForMember(dest => dest.OrderNumber, opt => opt.MapFrom(src => src.OrderNo))
.ForMember(dest => dest.OrderItemsDto, opt => opt.Ignore());//把目标model中的集合导航属性单体忽略
}
□ 视图
@model IEnumerable<OrderDto>
@foreach(var item in Model)
{
@item.OrderNumber
@item.CustomerName
@item.Total()
}
把源中的DateTime类型转换成int类型
□ 思路
要么直接通过MapFrom(src => src.DateTime.Hour)
要么实现IValueFormatter，TypeConverter<,>，ValueResolver<,>
□ Domain model
public class Order
{
public string OrderNo{get;set;}
public Customer Customer {get;set;}
public DateTime PurchaseDate{get;set;} //转换本属性
public IEnumerable<OrderItems> LineItmes{get;set;}
public bool ShipToHomeAddress{get;set;}
public decimal GetTotal()
{
return LineItems == null? : : LineItems.Sum(x => x.GetTotalPrice());
}
public Guid InternalId{get;set;}
}
□ View model
public class OrderDateDto
{
public int PurchaseHour{get;set;}
public int PurchaseMinute{get;set;}
public string CustomerName{get;set;}
}
□ 控制器
public ActionResult OrderDate()
{
var order = _repository.Get(3);
order.PurchaseDate = new DateTime(2011, 3, 15, 20, 30, 0);
Mapper.CreateMap<Order, OrderDateDto>()
.ForMember(dest => dest.PurchaseHour, opt => opt.MapFrom(src => src.PurcahseDate.Hour))
.ForMember(dest => dest.PurcaseMinute, opt => opt.MapFrom(src => src.PurchaseDate.Minute));
var model = Mapper.Map<Order, OrderDateDto>(order);
return View(model);
}
□ 视图
@model OrderDateDto
@Model.CustomerName
@Model.PurchaseHour
@Model.PurchaseMinute
把源中的bool类型转换成string类型
□ Domain model
public class Order
{
public string OrderNo { get; set; }
public Customer Customer { get; set; }
public DateTime PurchaseDate { get; set; }
public IEnumerable<OrderItems> LineItems { get; set; }
public bool ShipToHomeAddress { get; set; } //转换本属性
public decimal GetTotal()
{
return LineItems == null ? 0 : LineItems.Sum(x => x.GetTotalPrice());
}
public Guid InternalId { get; set; }
}
□ View model
public class OrderShipDto
{
public string ShipHome { get; set; }
public string CustomerName { get; set; }
}
□ 自定义解析器
public class CustomBoolResolver : ValueResolver<Order, string>
{
protected override string ResolveCore(Order source)
{
return source.ShipToHomeAddress? "Yes" : "No";
}
}
控制器
public ActionResult OrderShip()
{
var orders = _repository.GetAll();
Mapper.CreateMap<Order, OrderShipDto>()
.ForMember(dest => dest.ShipHome, opt => opt.ResolveUsing<CustomBoolResolver>());
var model = Mapper.Map<IEnumerable<Order>, IEnumerable<OrderShipDto>>(orders);
return View(model);
}
视图
@item.CustomerName
@item.ShipHome
把源中的集合导航属性IEnumerable<OrderItems> LineItems转换成目标中的计算数量的string类型
□ 思路
对于LineItems同时用到自定义ValueResolver<Order, int>和IValueFormatter。
□ Domain model
public class Order
{
public string OrderNo { get; set; }
public Customer Customer { get; set; }
public DateTime PurchaseDate { get; set; }
public IEnumerable<OrderItems> LineItems { get; set; }
public bool ShipToHomeAddress { get; set; }
public decimal GetTotal()
{
return LineItems == null ? 0 : LineItems.Sum(x => x.GetTotalPrice());
}
public Guid InternalId { get; set; }
}
□ View model
public class NumberOfOrderDto
{
public string CustomerName { get; set; }
public string NumberOfOrders { get; set; }
}
□ 自定义解析
public class CustomOrderCount : ValueResolver<Order, int>
{
protected override int ResolveCore(Order source)
{
return source.LineItems.Count();
}
}
□ 自定义formatter格式
public class FormatOrderCount : IValueFormatter
{
public string FormatValue(ResolutionContext context)
{
int num = (int).context.SourceValue;
if(num<=1)
return "Number of Order:" + num;
return "Number of Orders:" + num;
}
}
□ 控制器
public ActionResult NumberOfOrders()
{
var orders = _repository.GetAll();
orders.First().LineItems = new List<OrderItems>(); //在order类中的构造函数中没有初始化，所以这里要初始化
Mapper.CreateMap<Order, NumerOfOrderDto>()
.ForMember(dest => dest.NumberOfOrders, opt => {
opt.ResolveUsing<CutomOrderCount>();
opt.AddFormatter<FormatOrderCount>();
})
var model = Mapper.Map<IEnumerable<Order>, IEnumerable<NumberOfOrderDto>>(orders);
return View(model);
}
□ 视图
@model IEnumerable<NumberOfOrderDto>
@foreach(var order in Model)
{
@order.CustomerName
@order.NumberOfOrders
}