how can i add item to Combobox in wpf at runtime - wpf

Question

how can I bind data to Combobox at runtime? I use template field in Combobox and i try to update Combobox item source in code-behind. but not update xamarin my Combobox in form. and in combobox template field, i want to delete combobox item with a button that event name cbxDeleteStudent_Click. but i can't find comboxitem in code behind.
Please help me.
MyCodes:
<ComboBox x:Name="cbxStudents" Width="150" ItemsSource="{Binding}">
<ComboBox.ItemTemplate>
<DataTemplate>
<DockPanel Width="150">
<Label Content="{Binding StudentId}" x:Name="cbxStudentId"></Label>
<Label Content="{Binding StudentName}"></Label>
<Button Content="Sil" x:Name="cbxDeleteStudent" HorizontalAlignment="Right" Width="35"
CommandParameter="{Binding StudentId}" Click="cbxDeleteStudent_Click"></Button>
</DockPanel>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
Code Behind
private void btnAddNewStudent_Click(object sender, RoutedEventArgs e)
{
using (EmployeeDbContext db = new EmployeeDbContext())
{
Student newStudent = new Student()
{
StudentName = txtStudent.Text
};
db.Students.Add(newStudent);
if (db.SaveChanges() > 0)
{
MessageBox.Show(string.Format("{0} öğrencisi başarı ile eklenmiştir.", txtStudent.Text), "Bilgi", MessageBoxButton.OK);
txtStudent.Text = string.Empty;
(cbxStudents.ItemsSource as List<Student>).Add(newStudent);
}
}
}
for delete combobox item
private void cbxDeleteStudent_Click(object sender, RoutedEventArgs e)
{
using (EmployeeDbContext db = new EmployeeDbContext())
{
Student selectedStudent = db.Students.Find(int.Parse((sender as Button).CommandParameter.ToString()));
db.Students.Remove(selectedStudent);
db.SaveChanges();
}
((sender as Button).Parent as DockPanel).Children.Clear();
}

Answer 1

It looks like the the ItemSource used to bind to the ComboBox, is a List<Student>.
Use ObservableCollection(Of T) instead of List<T>, ObservableCollection provides notification when items get added, removed, or when the whole list is refreshed and the ComboBox items are updated, while List<T> doesn't.
Then you just need to add/remove the item from the ObservableCollection, without having to touch the ComboxBox's Items property.
To Add
(cbxStudents.ItemsSource as ObservableCollection<Student>).Add(newStudent);
To Remove
ObservableCollection<Student> students = cbxStudents.ItemsSource as ObservableCollection<Student>;
int studentId = int.Parse((sender as Button).CommandParameter.ToString());
Student selectedStudent = students.SingleOrDefault(s => s.StudentId == studentId);
students.Remove(selectedStudent);