LINQ：如何使用LINQ将深层嵌套对象压平

Question

我正试图将该模型压平成集合。

public class Category 
    { 
     public string name; 
     public string id;   
     public Subcategory subcategory; 
    } 


public class Subcategory 
{ 
    public string name; 
    public string id;   
    public List<Product> products; 
} 


public class Product 
{ 
    public string name; 
    public string id;   
    public Supplier1 supplier1; 
    public Supplier2 supplier2 
} 

public class Supplier1 
{ 
    public string name; 
    public string id;   

} 
public class Supplier2 
{ 
    public string name; 
    public string id;   

} 

我需要使用LINQ把它们变成以下类型的对象的集合：

public class MixedClass 
{ 
    public string CategoryId; 
    public string SubcategoryId;   
    public string ProductId ; 
    public string Supplier1Id ; 
    public string Supplier2Id ; 

} 

我已经试过，但的SelectMany我不能去得足够深。

Answer 1

你可以简单地这样做：

var results = 
    from c in Categories 
    from p in c.subcategory.products 
    select new MixedClass() 
    { 
     CategoryId = c.id, 
     SubcategoryId = c.subcategory.id, 
     ProductId = p.id, 
     Supplier1Id = p.supplier1.id, 
     Supplier2Id = p.supplier2.id, 
    }; 

或者如果你喜欢通顺语法：

var results = Categories 
    .SelectMany(c => c.subcategory.products, 
       (c, p) => new MixedClass() 
       { 
        CategoryId = c.id, 
        SubcategoryId = c.subcategory.id, 
        ProductId = p.id, 
        Supplier1Id = p.supplier1.id, 
        Supplier2Id = p.supplier2.id, 
       });