c# - AutoMapper mapping nested List object -

i trying map nested list dto object, not working. here tried. returns null. error is: an exception of type 'automapper.automappermappingexception' occurred in automapper.dll not handled in user code

public class ordersview_dto {     public int orderid { get; set; }     public string ordernumber { get; set; }     public float? ordertotal { get; set; }     public string lastname { get; set; }     public string firstname { get; set; }     public list<productsdto> productsdto { get; set; }  }  public class productsdto {       public int id { get; set; }      public int orderid { get; set; }   } 

this how mapping:

        mapper.createmap<orderheader, ordersview_dto>()         .formember(h => h.productsdto, k => k.mapfrom((m => m.orderlines)));          ienumerable<orderheader> orderslist = new ordersrepository().getorders();          ienumerable<ordersview_dto> ordersflow = mapper.map<ienumerable<orderheader>, ienumerable<ordersview_dto>>(orderslist); 

i sure problem relies in line: .formember(h => h.productsdto, k => k.mapfrom((m => m.orderlines))); productsdto , orderlines both lists.

here orderheader class:

 public class orderheader     {          public orderheader()         {             // set defaults here;             orderlines = new list<orderlines>();         }           public float? subtotal { get; set; }          public float? shipping { get; set; }          public string shipmethod { get; set; }          public float? tax { get; set; }            public int salesid { get; set; }          public string ipaddress { get; set; }          // mapping          public customer customer;         public ordercc ordercc;         public orderaddress orderaddress;         public list<orderlines> orderlines;       } 

your automapper map declaration correct.

can verify orderslist.orderlines not null or empty before map it? possible ordersrepository isn't giving or populating orderslist way think is.

ienumerable<orderheader> orderslist = new ordersrepository().getorders(); // check value of orderslist.orderlines.count here // (assuming orderlines ienumerable<t> 

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update

after verifying orderlines not empty, possible change productsdto declaration to:

public ienumerable<productsdto> productsdto { get; set; } 

there not reason specify list<>. possible getting type mismatch exception, because aren't able cast whatever orderlines list<>

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update 2

you trying map ienumerable<orderlines> ienumerable<productsdto>, aren't congruant types. have map also?

you need well:

mapper.createmap<orderline, productsdto>().formember(...