private async void SaveBtn_Clicked(object sender, EventArgs e)
{
var item = (Schooler.Class.Assignment)BindingContext;
// DateTime time = (DateTime)(deadlinePicker.GetValue(DatePicker.DateProperty));
// Assignment temp = new Assignment(0, nameEntry.Text, time);
if (idx < 0)
{
UserDao dao = new UserDao();
dao.AddAssignment(item);
// dao.AddAssignment(temp);
}
else
{
dao.Update(item);
}
await Navigation.PopAsync();
}