private void SaveBtnClick(Object sender, System.EventArgs e)
        {
            AddressBookLine myLine = new AddressBookLine();

            myLine.EmailAddress = EmailAddressTbx.Text;
            myLine.FirstName    = FirstNameTbx.Text;
            myLine.SecondtName  = SecondNameTbx.Text;
            myLine.PhoneNumber  = PhoneNumberTbx.Text;
            tempAddrBook.Add(myLine);
            AddrBookDGd.ItemsSource = null;
            AddrBookDGd.ItemsSource = tempAddrBook;
        }
        private void datagrid_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (e.AddedItems != null && e.AddedItems.Count != 0)
            {
                AddressBookLine line = e.AddedItems[0] as AddressBookLine;
                EmailAddressTbx.Text = line.EmailAddress;
                FirstNameTbx.Text    = line.FirstName;
                SecondNameTbx.Text   = line.SecondtName;
                PhoneNumberTbx.Text  = line.PhoneNumber;

                TempIndexBookList = GettingEmailIndexinList(line);
            }
        }
        private int GettingEmailIndexinList(AddressBookLine line)
        {
            int index = tempAddrBook.FindIndex(a => a.EmailAddress == line.EmailAddress);

            return(index);
        }