private async void ListView_OnItemTapped(object sender, ItemTappedEventArgs e)
        {
            TambahPeminjamanPage tambahPage = new TambahPeminjamanPage();

            Peminjaman item = (Peminjaman)e.Item;

            tambahPage.BindingContext       = item;
            ((ListView)sender).SelectedItem = null;
            await Navigation.PushAsync(tambahPage);
        }
 private async void MenuItem_OnClicked(object sender, EventArgs e)
 {
     TambahPeminjamanPage tambahPage = new TambahPeminjamanPage(true);
     await Navigation.PushAsync(tambahPage);
 }