c# - Selecting a sub-list with an associated string value -

assume have following:

public class classa {     public string description {get;set;}     public list<product> products {get;set;} }  public class classb {     public string description {get;set;}     public product singleproduct {get;set;} }  public class classc {     public list<classa> listofas {get;set;}     public list<classb> breakdownlistofas()     {         // critical point     } } 

at marked critical point, want return list of classb instances created examining listofas , decomposing such each instance of classb has single product , description classa instance in product resides.

example, if have:

var listofas = new list<classa> {     new classa {         description = "foo",         products = new list<product> { p1, p2 }     },     new classa {         description = "bar",         products = new list<product> { p3, p4 }     } }; 

then return value of classc.breakdownlistofas() should match:

new list<classb> {     new classb { description = "foo", product = p1 },     new classb { description = "foo", product = p2 },     new classb { description = "bar", product = p3 },     new classb { description = "bar", product = p4 }, } 

i know i'd use .selectmany() projecting sub-list, can't work out how achieve composition of projected sub-elements string parent object.

in linq method chain, this:

return listofas     .selectmany(a => a.products,                 (a, p) => new classb                                 {                                     description = a.description,                                     singleproduct = p                                 })     .tolist(); 

the trick create object in result selector using both description classa instance , product classa's list.