private void lsvBillExport_Click(object sender, EventArgs e)
 {
     if (lsvBillExport.SelectedItems.Count > 0)
     {
         DetailOfBillExport detail = detailOfBillExports.ElementAt(lsvBillExport.SelectedItems[0].Index);
         int count = detail.Count;
         foreach (Material material in materials)
         {
             if (material.IDMaterial == detail.IDMaterial)
             {
                 count += material.AmountLeft;
             }
         }
         fChangeNumberOfMaterialExport f = new fChangeNumberOfMaterialExport(count);
         f.Changed += ChangedDetailBillExport;
         f.ShowDialog();
     }
 }
        private void ChangedDetailBillExport(object sender, EventArgs e)
        {
            fChangeNumberOfMaterialExport f = sender as fChangeNumberOfMaterialExport;

            if (f != null)
            {
                DetailOfBillExport detail = detailOfBillExports.ElementAt(lsvBillExport.SelectedItems[0].Index);
                int count      = f.Value;
                int numberBack = detail.Count - count;
                detail.Count = count;
                foreach (Material item in materials)
                {
                    if (item.IDMaterial == detail.IDMaterial)
                    {
                        item.AmountLeft += numberBack;
                    }
                }
                LoadLsvBillExport();
                LoadLsvMaterial();
            }
        }