public void ExportToExcel() { SaveFileDialog sfd = new SaveFileDialog(); sfd.Filter = "Excel 2007 - 2016|*.xlsx"; sfd.Title = "选择计算文件"; if (sfd.ShowDialog() == DialogResult.OK) { if (File.Exists(sfd.FileName)) { File.Delete(sfd.FileName); } try { var exporttoexcel = new ExportCalculationSheet(Piles.ToList()); Task task = Task.Run(() => exporttoexcel.Export(sfd.FileName)) .ContinueWith(t => MessageBox.Show($"文件已保存至{sfd.FileName}", "保存成功", MessageBoxButtons.OK, MessageBoxIcon.Information), TaskContinuationOptions.OnlyOnRanToCompletion); //MessageBox.Show($"文件已保存至{sfd.FileName}", "保存成功", MessageBoxButtons.OK, MessageBoxIcon.Information); } catch (Exception e) { MessageBox.Show(e.ToString(), "输出错误!", MessageBoxButtons.OK, MessageBoxIcon.Error); } } }