AutoMapper在MVC中的运用07-映射在订单场景的例子

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

}