导出公共方法判断数据为空也需要导出文件

CallCenterCommon/CallCenter.Utility/NPOI/NPOIHelper.cs

         {
             try
             {
-                if (dt.Rows.Count > 0)
+                HSSFWorkbook workbook = new HSSFWorkbook();
+                ISheet sheet = workbook.CreateSheet("Sheet1");
+
+                ICellStyle HeadercellStyle = workbook.CreateCellStyle();
+                HeadercellStyle.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;
+                HeadercellStyle.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;
+                HeadercellStyle.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;
+                HeadercellStyle.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;
+                HeadercellStyle.Alignment = HorizontalAlignment.Center;
+                HeadercellStyle.FillForegroundColor = NPOI.HSSF.Util.HSSFColor.SkyBlue.Index;
+                HeadercellStyle.FillPattern = FillPattern.SolidForeground;
+                HeadercellStyle.FillBackgroundColor = NPOI.HSSF.Util.HSSFColor.SkyBlue.Index;
+
+                //字体
+                NPOI.SS.UserModel.IFont headerfont = workbook.CreateFont();
+                headerfont.Boldweight = (short)FontBoldWeight.Bold;
+                headerfont.FontHeightInPoints = 12;
+                HeadercellStyle.SetFont(headerfont);
+
+
+                //用column name 作为列名
+                int icolIndex = 0;
+                IRow headerRow = sheet.CreateRow(0);
+                if (cols == null || (cols != null && cols.Length == 0))
                 {
-                    HSSFWorkbook workbook = new HSSFWorkbook();
-                    ISheet sheet = workbook.CreateSheet("Sheet1");
-
-                    ICellStyle HeadercellStyle = workbook.CreateCellStyle();
-                    HeadercellStyle.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;
-                    HeadercellStyle.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;
-                    HeadercellStyle.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;
-                    HeadercellStyle.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;
-                    HeadercellStyle.Alignment = HorizontalAlignment.Center;
-                    HeadercellStyle.FillForegroundColor = NPOI.HSSF.Util.HSSFColor.SkyBlue.Index;
-                    HeadercellStyle.FillPattern = FillPattern.SolidForeground;
-                    HeadercellStyle.FillBackgroundColor = NPOI.HSSF.Util.HSSFColor.SkyBlue.Index;
-
-                    //字体
-                    NPOI.SS.UserModel.IFont headerfont = workbook.CreateFont();
-                    headerfont.Boldweight = (short)FontBoldWeight.Bold;
-                    headerfont.FontHeightInPoints = 12;
-                    HeadercellStyle.SetFont(headerfont);
-
-
-                    //用column name 作为列名
-                    int icolIndex = 0;
-                    IRow headerRow = sheet.CreateRow(0);
-                    if (cols == null || (cols != null && cols.Length == 0))
+                    foreach (DataColumn dc in dt.Columns)
                     {
-                        foreach (DataColumn dc in dt.Columns)
-                        {
-                            ICell cell = headerRow.CreateCell(icolIndex);
-                            cell.SetCellValue(dc.ColumnName);
-                            cell.CellStyle = HeadercellStyle;
-                            icolIndex++;
-                        }
+                        ICell cell = headerRow.CreateCell(icolIndex);
+                        cell.SetCellValue(dc.ColumnName);
+                        cell.CellStyle = HeadercellStyle;
+                        icolIndex++;
                     }
-                    else
+                }
+                else
+                {
+                    foreach (string dc in cols)
                     {
-                        foreach (string dc in cols)
-                        {
-                            ICell cell = headerRow.CreateCell(icolIndex);
-                            cell.SetCellValue(dc);
-                            cell.CellStyle = HeadercellStyle;
-                            icolIndex++;
-                        }
+                        ICell cell = headerRow.CreateCell(icolIndex);
+                        cell.SetCellValue(dc);
+                        cell.CellStyle = HeadercellStyle;
+                        icolIndex++;
                     }
-                    ICellStyle cellStyle = workbook.CreateCellStyle();
-
-                    //为避免日期格式被Excel自动替换，所以设定 format 为 『@』 表示一率当成text來看
-                    cellStyle.DataFormat = HSSFDataFormat.GetBuiltinFormat("@");
-                    cellStyle.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;
-                    cellStyle.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;
-                    cellStyle.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;
-                    cellStyle.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;
+                }
+                ICellStyle cellStyle = workbook.CreateCellStyle();
 
+                //为避免日期格式被Excel自动替换，所以设定 format 为 『@』 表示一率当成text來看
+                cellStyle.DataFormat = HSSFDataFormat.GetBuiltinFormat("@");
+                cellStyle.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;
+                cellStyle.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;
+                cellStyle.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;
+                cellStyle.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;
 
-                    NPOI.SS.UserModel.IFont cellfont = workbook.CreateFont();
-                    cellfont.Boldweight = (short)FontBoldWeight.Normal;
-                    cellStyle.SetFont(cellfont);
 
+                NPOI.SS.UserModel.IFont cellfont = workbook.CreateFont();
+                cellfont.Boldweight = (short)FontBoldWeight.Normal;
+                cellStyle.SetFont(cellfont);
+                if (dt.Rows.Count > 0)
+                {
                     //建立内容行
                     int iRowIndex = 0;
                     foreach (DataRow dr in dt.Rows)
                     {
                         sheet.AutoSizeColumn(i);
                     }
+                }
+                using (MemoryStream ms = new MemoryStream())
+                {
+                    workbook.Write(ms);
 
-                    using (MemoryStream ms = new MemoryStream())
-                    {
-                        workbook.Write(ms);
-
-                        HttpContext curContext = HttpContext.Current;
+                    HttpContext curContext = HttpContext.Current;
 
 
-                        // 设置编码和附件格式
-                        curContext.Response.ContentType = "application/vnd.ms-excel";
-                        curContext.Response.ContentEncoding = Encoding.UTF8;
-                        curContext.Response.Charset = "";
-                        curContext.Response.AppendHeader("Content-Disposition",
-                            "attachment;filename=" + HttpUtility.UrlEncode(Name + ".xls", Encoding.UTF8));
+                    // 设置编码和附件格式
+                    curContext.Response.ContentType = "application/vnd.ms-excel";
+                    curContext.Response.ContentEncoding = Encoding.UTF8;
+                    curContext.Response.Charset = "";
+                    curContext.Response.AppendHeader("Content-Disposition",
+                        "attachment;filename=" + HttpUtility.UrlEncode(Name + ".xls", Encoding.UTF8));
 
-                        curContext.Response.BinaryWrite(ms.GetBuffer());
+                    curContext.Response.BinaryWrite(ms.GetBuffer());
 
-                        workbook = null;
-                        ms.Close();
-                        ms.Dispose();
+                    workbook = null;
+                    ms.Close();
+                    ms.Dispose();
 
-                        curContext.Response.End();
-                    }
+                    curContext.Response.End();
                 }
+
                 return "";
             }
             catch