c# - ComboBox not autoselecting initial value -

i have combobox bound list of people in simple viewmodel. selectedperson set in constructor of viewmodel, when run application, combobox not set initial value. doing wrong?

notice 2 instances of myperson class should considered equal when have same id.

important: cannot modify myperson override equals (it's third party).

the option i've seen far user adapter pattern wrap instances of class , implement custom equals method there.

i feel there should better method native wpf match items list kind of "key". in case, list of items , selected item come different sources, , that's why have id property acting primary key.

please, take @ code, i've played selectedvalue , selectedvaluepath, nothing works.

<window x:class="test.mainwindow"         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"         xmlns:vm="clr-namespace:test"         mc:ignorable="d"         x:name="root"         title="mainwindow" height="350" width="525">     <window.datacontext>         <vm:mainviewmodel />     </window.datacontext>     <combobox itemssource="{binding people}" selecteditem="{binding selectedperson}" selectedvaluepath="id"               displaymemberpath="name"               selectedvalue="{binding selectedperson}" /> </window> 

and viewmodel datacontext:

public class mainviewmodel {     public mainviewmodel()     {         selectedperson = new myperson { name = "mary", id = 1 };     }      public myperson selectedperson { get; set; }      public ienumerable<myperson> people { get; } = new list<myperson>()     {         new myperson() {name = "mary", id = 1 },         new myperson() {name = "john", id = 2 },     }; }  public class myperson {     public string name { get; set; }     public int id { get; set; } } 

the problem new object create here

selectedperson = new myperson { name = "mary", id = 1 }; 

isnt' same in list equals method return false in cases!

as else suggested, have real object in list doing this:

public mainviewmodel(){    selectedperson = people.first(x=> x.name.equals("mary")); //or: x.id == 1 } 

but there solution: can override equals function in myperson class, every myperson instance same name and/or id indeed seen same person.

edit

as you're using viewmodels in project, better if had viewmodel mypersonclass too. solve problems and make design better!