文件的下载

1.将数据库的数据保存到文本文件中:

context.Response.ContentType = "text/plain";
//增加另存为功能
//增加Content-Disposition是告诉浏览器，这个返回的内容是"附件形式"，要给用户保存,filename是建议的文件名
context.Response.AddHeader("Content-Disposition", "attachment;filename=" + context.Server.UrlEncode("动态文件.txt"));
DataTable table = SQLHelper.ExecuteReader("select * from userinfo");
foreach (DataRow row in table.Rows)
{
    context.Response.Write(row["name"].ToString() + "\t" + row["age"].ToString() + "\r\n");
}

2.将数据库的数据保存到EXCEL中

context.Response.ContentType = "application/ms-excel";
context.Response.AddHeader("Content-Disposition", "attachment;filename=" +
    context.Server.UrlEncode("人员列表.xls"));
IWorkbook workbook = new HSSFWorkbook();//new XSSFWorkbook();//xlsx
ISheet sheet = workbook.CreateSheet("人员列表");
DataTable dt = SQLHelper.ExecuteReader("select * from Users");
for (int i = 0; i < dt.Rows.Count; i++)
{
    IRow excelRow = sheet.CreateRow(i);
    DataRow dataRow = dt.Rows[i];
    ICell cell0 = excelRow.CreateCell(0);
    cell0.SetCellValue((string)dataRow["username"]);

    ICell cell1 = excelRow.CreateCell(1);
    cell1.SetCellValue((int)dataRow["age"]);
}
workbook.Write(context.Response.OutputStream);