NPOI导出Excel文件的文章很多了，但是没看到easy-ui datagrid表格直接导出Excel文件的，要显示中文Title和Excel文件每列列宽和页面上看到的基本相符。这里可能是个实现，不是最佳，写出来给有用的人参考。可能在通用二字上做得还不是特别好，有好的方法请留言指正。
效果：
编码过程：
1、js
//-----------------------------------------------------// @description 返回grid的(可见的)所有行给后端导出Excel用// @param {string} table 表格ID// @returns rows// @author 肖峰//------------------------------------------------------function getGridDataToExcelExport(table) { var allRows = $("#" + table).datagrid("getRows"); return allRows;}//-----------------------------------------------------// @description 返回grid的所有列// @param {string} table 表格ID// @returns rows// @author 肖峰function getGridColumnFields(table) { var allCols = $("#" + table).datagrid("getColumnFields"); return allCols;}//-----------------------------------------------------// @description 返回grid的所有列的选项title、列宽等// @param {string} table 表格ID// @returns rows// @author 肖峰function getGridColumnFieldsOptions(table) { var allColsTitle = $("#" + table).datagrid("options").columns; return allColsTitle;} //导出结果集到Excel function exportGrid() { if (getGridDataToExcelExport("ResultGrid").length == 0) { alertMsg("系统提示", "记录数为0，不需要导出！", "error"); return; } var entity = {}; entity.GridRows = getGridDataToExcelExport("ResultGrid"); entity.GridColumnOptions = getGridColumnFieldsOptions("ResultGrid"); entity.ExportFileName = '产品箱盒对应查询结果.xls'; POVOS.BarCode.Website.BoxCorrespondingQuery.ExportGridToExcelFileAndDownload(entity, function (p) { location.href = "ExportExcelFile.ashx?ExcelFileID=" + p.value; }); }//导出结果集到Excel function exportGrid() { if (getGridDataToExcelExport("ResultGrid").length == 0) { alertMsg("系统提示", "记录数为0，不需要导出！", "error"); return; } var entity = {}; entity.GridRows = getGridDataToExcelExport("ResultGrid"); entity.GridColumnOptions = getGridColumnFieldsOptions("ResultGrid"); entity.ExportFileName = '产品物流流向查询结果.xls'; POVOS.BarCode.Website.ProductTransQuery.ExportGridToExcelFileAndDownload(entity, function (p) { location.href = "ExportExcelFile.ashx?ExcelFileID="+p.value; }); } 2、后台代码，前台使用ajaxpro2调用后台方法，传递前端页面grid行列记录的Json格式。
////// 形成Excel对应的文件流存在数据库里，返回给前端File GUID /// /// ///[AjaxMethod] public string ExportGridToExcelFileAndDownload(JavaScriptObject entity) { var gridRows = (JavaScriptArray)entity["GridRows"]; var gridOptions = (JavaScriptArray)entity["GridColumnOptions"]; var gridOptionList = (JavaScriptArray)gridOptions[0]; //可见的列 List gridCols = new List (); foreach (JavaScriptObject j in gridOptionList) { if (j.Value.IndexOf("hidden") == -1) { gridCols.Add(j); } } var fileName = entity["ExportFileName"].ToString(); string tempFileName = AppDomain.CurrentDomain.BaseDirectory + "CommonExcelFile.xls"; FileStream fs = new FileStream(tempFileName, FileMode.Open, FileAccess.Read); var workBook = new HSSFWorkbook(fs); workBook.SetSheetName(0,"查询结果"); var sheet = workBook.GetSheetAt(0); //表头(列)，第一行 int newColIndex = 0; var titleRow = sheet.CreateRow(newColIndex); int cIndex = 0; foreach (JavaScriptObject j in gridCols) { titleRow.CreateCell(cIndex).SetCellValue(j["title"].ToString()); int width = int.Parse(j["width"].ToString()) / 6; if (width > 255) width = 250; sheet.SetColumnWidth(cIndex, width*256); cIndex++; } //行记录 for (int rowIndex = 0; rowIndex < gridRows.Count; rowIndex++) { newColIndex++; var row = sheet.CreateRow(newColIndex); var jsonEntity = gridRows[rowIndex] as JavaScriptObject; for (int colIndex = 0; colIndex < gridCols.Count; colIndex++) { string cellValue = string.Empty; JavaScriptObject colOption = (JavaScriptObject)gridCols[colIndex]; string field = colOption["field"].ToString(); if (jsonEntity[field] != null) cellValue = jsonEntity[field].ToString(); row.CreateCell(colIndex).SetCellValue(cellValue); } } MemoryStream newFile = new MemoryStream(); sheet.Workbook.Write(newFile); using (POVOSEntities db = new POVOSEntities()) { var resultFile = new ExportFileEntity(); resultFile.FileGuid = Guid.NewGuid(); resultFile.FileName = fileName; resultFile.FileCreateDateTime = DateTime.Now; resultFile.FileStreamByte = newFile.GetBuffer(); db.AddToExportFileEntity(resultFile); db.SaveChanges(); return resultFile.FileGuid.ToString(); } }
3、文件下载使用一般处理程序，接收QueryString里传的文件ID，返回给前端Excel文件。
using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.SessionState;using NPOI.SS.UserModel;using NPOI.HSSF.UserModel;using BarCode.DataAccess;namespace POVOS.BarCode.Website{ /// /// 读取数据库Excel文件并下载 /// public class ExportExcelFile : IHttpHandler, IRequiresSessionState { public void ProcessRequest(HttpContext context) { using (POVOSEntities db = new POVOSEntities()) { Guid fileID = new Guid(context.Request["ExcelFileID"] as string); var fileEntity = db.ExportFileEntity.Where(e => e.FileGuid == fileID).FirstOrDefault(); string filename = string.Format("[{0}]{1}", DateTime.Now.ToString("yyMMddHHmmss"), fileEntity.FileName); context.Response.ContentType = "application/vnd.ms-excel"; context.Response.AddHeader("Content-Disposition", string.Format("attachment;filename={0}", context.Server.UrlEncode(filename))); context.Response.Clear(); context.Response.BinaryWrite(fileEntity.FileStreamByte); context.Response.End(); } } public bool IsReusable { get { return false; } } }}
总结一下，遇到以下几个问题：
1、如何传递datagrid的行列记录到后置代码里，形成Excel文件。
2、NPOI的使用，如果控制列宽，对齐样式等。
3、下载时文件名显示为乱码。
4、解析前端页面传递过来的JSON，比如某些列没有"hidden"选项等。