private void btnChecksum_Click(object sender, EventArgs e) { OpenFileDialog dlg = new OpenFileDialog(); dlg.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"; dlg.FilterIndex = 2; dlg.RestoreDirectory = true; if (dlg.ShowDialog() == DialogResult.OK) { ChinaList list = new ChinaList(dlg.FileName); try { list.Update(); list.Validate(); MessageBox.Show("Succeeded!", "", MessageBoxButtons.OK, MessageBoxIcon.Information); } catch (CustomError ex) { MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } catch (Exception ex) { MessageBox.Show(ex.ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } } }