private void ekle_Click(object sender, RoutedEventArgs e)
{
OgrenciW ogrYonetim = new OgrenciW(new Ogrenci());
ogrYonetim.ShowDialog();
Yenile();
}
protected void HandleDoubleClick(object sender, MouseButtonEventArgs e)
{
Ogrenci ogrenci = ((ListViewItem)sender).Content as Ogrenci;
OgrenciW ogrYonetim = new OgrenciW(ogrenci);
ogrYonetim.ShowDialog();
Yenile();
}