NPOI还是比较好用的，引用dll程序集即可

1创建workbook和工作流

HSSFWorkbook workbook = new HSSFWorkbook();
MemoryStream ms = new MemoryStream();

2这里是一个多sheet的例子，可以通过循环一个个生成

1 List listtable = new List();
2 for(int t = 1; t < = listtable.Count();t++) 3 { 4 DataTable tempTable = listtable[t-1]; 5 //增加sheet,listname是一个List作为表明
6 HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet(listname[t-1]);
7 HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0);
8 foreach(DataColumn column in tempTable.Columns)
9 {
10 //创建列
11 headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
12 }
13 int rowIndex = 1;
14 foreach(DataRow row in tempTable.Rows)
15 {
16 //创建行
17 HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex);
18 foreach(DataColumn column in tempTable.Columns)
19 {
20 dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
21 }
22 rowIndex++;
23 }
24 }

3工作中的sheet都创建好之后，写入流

workbook.Write(ms);

4最后返回给浏览器端

byte[] strmByte = ms.ToArray();
ms.Dispose();
Response.ClearContent();
Response.ContentEncoding = System.Text.Encoding.UTF8;
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition","attachment;fileName="+"name.xlsx");
Response.BinaryWrite(strmByte);