IValueConverter and Combobox

Hi All

I have an Oberserveable Collection of Type Student. The Student Class has properties First Name and Last name. Initally, I used to show just the First Name in the Combo Box for which I used following bindings.

                            <ComboBox Grid.Row="3" Grid.Column="1" Name="cboStudent" ItemsSource="{Binding Path=StudentCollection}"  DisplayMemberPath="FirstName" SelectedValue="{Binding Path=CurrentStudent,Mode=TwoWay}"></ComboBox>

Please note that I am binding the selected Item to CurrentStudent

But Now that i needed to show the fullname in the combobox, I used a IValueConverter. 

 class CStudentFormatter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            //.Count ==0;

            if ((value as System.Collections.ObjectModel.ObservableCollection<Student>).Count()==0)
            {
                return 1;
            }
            System.Collections.ObjectModel.ObservableCollection<Student> k = (value as System.Collections.ObjectModel.ObservableCollection<Student>);

            List<string> returnValue = new List<string>();

            foreach (var item in k)
            {
                returnValue.Add(string.Format("{0} ({1})", item.FirstName, item.LastName));
            }

            return returnValue;
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

I reformatted by orginal combobox binding as following.

<ComboBox Grid.Row="7" Grid.Column="5" 
                                      ItemsSource="{Binding Path=StudentCollection,Mode=TwoWay, UpdateSourceTrigger=PropertyChanged , Converter={StaticResource CStudentFormatter}}"></ComboBox>

Now, I am able to get the desired Full name in the combo box , but I am not able to get the selected Item back to the Current Student on selection. I tried following

SelectedItem="{Binding Path=CurrentStudent, Converter={StaticResource CStudentFormatter}}

Can anyone please help me ?

Thanks in Advance.

Anu

Anu Viswan : www.AnuViswan.blogspot.com