excel表格的B1单元格能读出数据，但写不进去

using (ExcelPackage resultExcel = new ExcelPackage(new FileInfo(@"..\..\出货报告\" + textBox1.Text + ".xlsx")))
                        {
                            ExcelWorksheet resultWS = resultExcel.Workbook.Worksheets["出货报告"];//目标工作表格
                            MessageBox.Show(((string)(resultWS.Cells["B1"].Value)).Replace("****", "P20"));
                            resultWS.Cells["B1"].Value = ((string)(resultWS.Cells["B1"].Value)).Replace("****", "P20");
                            resultWS.Cells["B1"].Style.Font.Name = "Arial";
                            resultWS.Cells["B1"].Style.Font.Bold = true;
                            resultWS.Cells["B1"].Style.Font.Size = 18;
                            resultWS.Cells["B1"].Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;
                            resultWS.Cells["B1"].Style.VerticalAlignment = ExcelVerticalAlignment.Center;
                            resultWS.Cells["B1"].Style.WrapText = true;
                            resultWS.Column(11).Width = 50;
                            resultExcel.Save();
                        }

调用saveas，另存为其他文件