WP8 Pivot Overlapped When Changed Binding Source - pivot

Question

I found a problem when i use the pivot control in the Windows Phone 8 SDK.
The pivot binds to a list named Students and set a button when click it，Will new a new student object and set it to Students[2] as new value. This has lead to the overlapping problem shown in the screenshot below. Has anyone else had this problem in the WP8 SDK?
Here is the code
public MainPage()
{
InitializeComponent();
this.DataContext = this;
// Sample code to localize the ApplicationBar
//BuildLocalizedApplicationBar();
InitiList();
}
private void Button_Click_1(object sender, RoutedEventArgs e)
{
int index = 2;
Students[index] = new Student();
Students[index].Name = "tian";
Students[index].College = "shida";
}
private ObservableCollection<Student> _students;
public ObservableCollection<Student> Students
{
get { return _students; }
set
{
_students = value;
RaisePropertyChanged("Students");
}
}
private void InitiList()
{
Students = new ObservableCollection<Student>();
Students.Add(new Student { Name="a",College="aa"});
Students.Add(new Student { Name = "b", College = "aa" });
Students.Add(new Student { Name = "c", College = "aa" });
Students.Add(new Student { Name = "d", College = "aa" });
Students.Add(new Student { Name = "e", College = "aa" });
}
Ckeck this o/p image:

Answer 1

You're modifying Students but RaisePropertyChanged isn't getting fired because accessing Students doesn't fire Set, which calls RaisePropertyChanged. This could be the problem, I can't test it right now.

Answer 2

I experience the same issue, and I fixed it by adding the items to the ObservableCollection in the constructor instead of using the Add method. It appears to be a bug with the ObservableCollection class. Try changing your code to:
private void InitiList()
{
Students = new ObservableCollection<Student>(new [] {
new Student { Name="a",College="aa"}),
new Student { Name = "b", College = "aa" }),
new Student { Name = "c", College = "aa" }),
new Student { Name = "d", College = "aa" }),
new Student { Name = "e", College = "aa" })
});
}