映射LinqToEntities加入到視圖模型

Question

我有以下型號和的ViewModels（編輯爲了簡潔）：

 Order Model: 
      OrderId 
      ShippingAddressId 
      ..... 
    Address Model: 
      AddressId 
      ..... 
    OrderViewModel: 
      Some Property from Order Model and Address Model 

如何內部聯接兩個表，並映射到一個視圖模型？

var query= from o in ctx.Orders 
     join addr in ctx.Addresses 
     on o.ShippingAddressId equals addr.AddressId 
     select new OrderViewModel.InjectFrom(o) 
           .InjectFrom(addr) 
           as OrderViewModel; 

此代碼無效。

Answer 1

首先，您需要兌現與ToList結果：

var query = (from o in ctx.Orders 
      join addr in ctx.Addresses 
      on o.ShippingAddressId equals addr.AddressId 
      select new { o, addr } 
      ).ToList() 
      .Select(x => new OrderViewModel().InjectFrom(x.o) 
               .InjectFrom(x.addr) 
          as OrderViewModel);