I know this question has been asked to death, but I have tried lots of the suggested answers I have found and the Combo Box is still not populating when I start the WPF in VS201
As for me, simpliest way is XmlSerializer.
public class Person
{
    public string personName;
    public string personEmail;
    public string personReports;
}
public class People
{
    [XmlElement("Person")]
    public List Persons;
}
 Load data:
var people = (People)new XmlSerializer(typeof(People)).Deserialize(stream);
employeeNameBox.ItemsSource = people.Persons;
ComboBox code: