reportviewer在web端手写代码导出excel文件

private void Page_Load(object sender, System.EventArgs e)
{
this.rdlViewer.ProcessingMode = ProcessingMode.Local;
this.rdlViewer.LocalReport.ReportPath = @"d:\Group+Process+by+Steps+(+Open+)+report.rdl";
}

protected void Button1_Click(object sender, EventArgs e)
{
Warning[] warnings;
string[] streamids;
string mimeType;
string encoding;
string extension;
byte[] bytes = rdlViewer.LocalReport.Render("Excel", null, out mimeType, out encoding, out extension,
out streamids, out warnings);
FileStream fs = new FileStream(@"d:\output.xls", FileMode.Create);
fs.Write(bytes, 0, bytes.Length);
fs.Close();
//File.Delete(@"d:\output.xls");
}