更新ComboBox源不会更新ComboBox

Question

I have a ComboBox whose ItemSource is bound to an ObservableCollection of type Person called PersonsList. The DisplayMemberPath on this ComboBox is set to FullName (which just returns the First Name + Last Name)

Person has various things stored in it such as First Name, Last Name, Phone Number, Address, etc.

Now when I update a person in PersonsList, I update the appropriate data fields and call OnPropertyChanged("PersonsList"). Now my issue occurs when I go back to view that ComboBox. If I've updated the First or Last Name of a Person, it doesn't update here. However, when I click on the person that should have been updated, it displays the newly updated first/last name correctly.

Here are 2 pictures to see what I mean: https://imgur.com/a/fP6apoX

Finally, here is my XAML code:

ComboBox ItemsSource="{Binding PersonsList, UpdateSourceTrigger=PropertyChanged}" 
DisplayMemberPath="FullName"/>

Answer 1

You need to modify your Person class as given below, since the property mapped with View belongs to the Person class, so the property changed event needs to be fired by the Person Class

public class Person : INotifyPropertyChanged
{
    /// <summary>
    /// Property Changed Event Handler
    /// </summary>
    public event PropertyChangedEventHandler PropertyChanged;

    // Create the OnPropertyChanged method to raise the event
    protected void OnPropertyChanged(string name)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(name));
        }
    }

    private String _FirstName;
    public String FirstName {
        get {
            return _FirstName;
        }
        set {
            _FirstName = value;
            OnPropertyChanged(nameof(FirstName));
        }
    }

    private String _LastName;
    public String LastName
    {
        get
        {
            return _LastName;
        }
        set
        {
            _LastName = value;
            OnPropertyChanged(nameof(LastName));
        }
    }

    private String _FullName;
    public String FullName
    {
        get
        {
            return _FullName;
        }
        set
        {
            _FullName = value;
            OnPropertyChanged(nameof(FullName));
        }
    }


}