How can I instantiate and add to a class inside a foreach loop in C# -

i have code want use log error messages. made 2 classes hold messages:

public class httpstatuserrors {     public httpstatuserrors()     {         this.details = new list<httpstatuserrordetails>();     }     public string header { set; get; }     public ilist<httpstatuserrordetails> details { set; get; } } public class httpstatuserrordetails {     public httpstatuserrordetails()     {         this.details = new list<string>();     }     public string header { set; get; }     public ilist<string> details { set; get; } } 

i think way not 100% sure , welcome suggestions.

what in first class store header in example "validation messages". in detail object store header showed entity error , in details store validation errors.

what confused on how should instantiate classes. have done far. think correct. how can add details need add:

catch (dbentityvalidationexception ex) {     var msg = new httpstatuserrors();     msg.header = "validation error";      foreach (var eve in ex.entityvalidationerrors)     {         var header = string.format("entity of type \"{0}\" in state \"{1}\" has following validation errors:",             eve.entry.entity.gettype().name, eve.entry.state);         foreach (var ve in eve.validationerrors)         {             var detail = string.format("- property: \"{0}\", error: \"{1}\"",                 ve.propertyname, ve.errormessage);         }      }  }. 

instantiate collections in details properties. instantiate new items, , add them collections in loop:

var msg = new httpstatuserrors(); msg.header = "validation error"; msg.details = new list<httpstatuserrordetails>();  foreach (var eve in ex.entityvalidationerrors) {     var detail = new httpstatuserrordetails()     detail.header = string.format("entity of type \"{0}\" in state \"{1}\" has following validation errors:",         eve.entry.entity.gettype().name, eve.entry.state);      detail.details = new list<string>();     foreach (var ve in eve.validationerrors)     {         detail.details.add(string.format("- property: \"{0}\", error: \"{1}\"",             ve.propertyname, ve.errormessage));     }      msg.details.add(detail); } 

btw can use linq that:

var msg = new httpstatuserrors(); msg.header = "validation error"; msg.details =     ex.entityvalidationerrors       .select(eve => new httpstatuserrordetails {                 header = string.format("entity of type \"{0}\" in state \"{1}\" has following validation errors:", eve.entry.entity.gettype().name, eve.entry.state)                 details = eve.validationerrors                          .select(ve => string.format("- property: \"{0}\", error: \"{1}\"", ve.propertyname, ve.errormessage))                          .tolist()        }).tolist(); 

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also extension methods syntax:

 public static httpstatuserrors tohttpstatuserrors(       dbentityvalidationexception ex)  {       return new httpstatuserrors {           header = "validation error",           details = ex.entityvalidationerrors                       .select(eve => eve.tohttpstatuserrordetails())                       .tolist()       };  }   public static httpstatuserrordetails tohttpstatuserrordetails(       dbentityvalidationresult eve)  {       return new httpstatuserrordetails {         header = string.format("entity of type \"{0}\" in state \"{1}\" has following validation errors:",                                eve.entry.entity.gettype().name, eve.entry.state),         details = eve.validationerrors                      .select(ve => ve.toerrordescription())                      .tolist()       };  }   public static string toerrordescription(       dbvalidationerror ve)  {       return string.format("- property: \"{0}\", error: \"{1}\"",                            ve.propertyname, ve.errormessage);  } 

usage of such methods like:

catch (dbentityvalidationexception ex) {     var msg = ex.tohttpstatuserrors(); }