C#导出excel

方式一,AppLibrary.WriteExcel.XlsDocument:

　　所用的库及库源码为:AppLibrary.WriteExcel.XlsDocument,这种方式默认是以excel2003的方式输出(即使机子上只安装office2010),而excel2003最多允许65536行,适合输出比较小的数据量.例如:

 1 /// <summary>
 2     /// 通过"AppLibrary.WriteExcel.XlsDocument",以.xls方式输出.
 3     /// </summary>
 4     public void WriteAsXLS() {
 5         AppLibrary.WriteExcel.XlsDocument doc = new AppLibrary.WriteExcel.XlsDocument();
 6         doc.FileName = "Report.xls";
 7
 8         //获得数据库前30条记录.
 9         var data = GetTopRecords(30).ToArray<t_review>();
10         const int sheetMaxRecord = 10;  //每个sheet最多的行数.
11         int curRow = 2; //开始游标.
12
13         int sheetNum = 1;   //sheet序号.
14         AppLibrary.WriteExcel.Worksheet sheet = null;
15
16         for (int s = 0; s < data.Length; s++) {
17             if (s % sheetMaxRecord == 0) {
18                 sheet = doc.Workbook.Worksheets.Add("sheet-" + sheetNum++);
19                 AddHead(sheet);
20
21                 curRow = 2;
22             }
23             AppLibrary.WriteExcel.Cells cells = sheet.Cells;
24
25             cells.Add(curRow, 1, data[s].votes);
26             cells.Add(curRow, 2, data[s].user_id);
27             cells.Add(curRow, 3, data[s].review_id);
28             cells.Add(curRow, 4, data[s].stars);
29             cells.Add(curRow, 5, data[s].date);
30             cells.Add(curRow, 6, data[s].text);
31             cells.Add(curRow, 7, data[s].type);
32             cells.Add(curRow, 8, data[s].business_id);
33
34             curRow++;
35         }
36         doc.Send();
37         Response.Flush();
38         Response.End();
39     }

获得记录的GetTopRecords方法为:

1 IQueryable<t_review> GetTopRecords(int topNum) {
2         ReviewDataContext re = new ReviewDataContext();
3         return (from r in re.t_reviews
4                 select r).Take<t_review>(topNum);
5     }

通过这种方式,处理大型数据的时候,容易抛出 System.OutOfMemoryException 异常,例如,我的数据库量为 一百多万条,就不能使用这种方式,即使产生多个sheet,例如:

 1 public void WriteAsXLS() {
 2         AppLibrary.WriteExcel.XlsDocument doc = new AppLibrary.WriteExcel.XlsDocument();
 3         doc.FileName = "Report.xls";
 4
 5         ReviewDataContext re = new ReviewDataContext();
 6         var data = from r in re.t_reviews
 7                    select r;
 8         const int sheetMaxRecord = 60000;   //每个sheet最多的行数.
 9         int curRecord = 0; //实际记录号.
10         int curRow = 2; //当前待写入sheet中的行号.
11
12         int sheetNum = 1;   //sheet序号.
13         AppLibrary.WriteExcel.Worksheet sheet = null;
14
15         foreach (var r in data) {
16             if (curRecord % sheetMaxRecord == 0) {
17                 sheet = doc.Workbook.Worksheets.Add("sheet-" + sheetNum++);
18                 AddHead(sheet);
19
20                 curRow = 2;
21             }
22             AppLibrary.WriteExcel.Cells cells = sheet.Cells;
23
24             cells.Add(curRow, 1, r.votes);
25             cells.Add(curRow, 2, r.user_id);
26             cells.Add(curRow, 3, r.review_id);
27             cells.Add(curRow, 4, r.stars);
28             cells.Add(curRow, 5, r.date);
29             cells.Add(curRow, 6, r.text);
30             cells.Add(curRow, 7, r.type);
31             cells.Add(curRow, 8, r.business_id);
32
33             curRecord++;
34         }
35         doc.Send();
36         Response.Flush();
37         Response.End();
38     }