1. protected void btn_ToExcel_Click(object sender, EventArgs e) 
2.     { 
3.         Response.ClearContent(); 
4.         Response.AddHeader("content-disposition","attachment; filename=MyExcelFile.xls"); 
5.         Response.ContentType = "application/excel"; 
6.         Response.Write(GetDataTableHtml((DataTable)ViewState["tt"])); 
7.         Response.End(); 
8.     } 
9.  
10.  
11. private string GetDataTableHtml(DataTable dt) 
12.     { 
13.         StringBuilder sb = new StringBuilder(); 
14.         sb.Append("<table cellspacing=\"0\" rules=\"all\" border=\"1\" style=\"border-collapse:collapse;\">"); 
15.         sb.Append("<tr>"); 
16.         foreach (DataColumn column in dt.Columns) 
17.         { 
18.             sb.AppendFormat("<td>{0}</td>", column.Caption); 
19.         } 
20.         sb.Append("</tr>"); 
21.  
22.         foreach (DataRow row in dt.Rows) 
23.         { 
24.             sb.Append("<tr>"); 
25.             for (int i = 0; i < dt.Columns.Count;i++ ) 
26.             { 
27.                 string html = row[i].ToString(); 
28.                 sb.AppendFormat("<td>{0}</td>", html); 
29.             } 
30.             sb.Append("</tr>"); 
31.         } 
32.         sb.Append("</table>"); 
33.         return sb.ToString(); 
34.       }

ExtAspNet从DataTable里导出Excel