private void btnDownLoad_Click(object sender, EventArgs e) { btnClose.Enabled = false; btnDownLoad.Enabled = false; try { downloader.DownLoadBaseData( ); } catch (Exception err) { MessageBox.Show(err.Message); ListViewItem item = new ListViewItem( ); item.Text = err.Message; lvwMsg.Items.Add(item); } finally { btnClose.Enabled = true; btnDownLoad.Enabled = true; } }