//载入报表参数
    private void ReportInput()
    {
        DataTable dt = new DataTable();
        if ((CheckShop.Checked == true) && (DDLShop.SelectedValue != ""))
        {
            string shop = DDLShop.SelectedItem.Value.ToString().Trim();
            string text = DDLCX.SelectedItem.Value.ToString().Trim();
            string value = string.Empty;
            if (text == "null")
            {
                value = null;
            }
            else
            {
                value = DDLCon.SelectedItem.Value.ToString().Replace(" 0:00:00", "");
            }
            dt = service.yyhz(jbtj, "tbl_jiebantongji", "shop_no", shop, text, value);
        }
        else
        {
            dt = service.yyhz(jbtj, "tbl_jiebantongji");
        }

        string reportPath = Server.MapPath("~/Reports/jiebantongji.rpt");
        report.Load(reportPath);
        report.SetDatabaseLogon("sa", "");
        report.SetDataSource(dt);
    }
 /// <summary>
    /// 报表导出功能实现
    /// </summary>
    protected void btnSave_Click(object sender, EventArgs e)
    {
        ReportInput();
        //导出类型
        string contenttype = string.Empty;
        //导出的文件类型
        string fileType = DDLSaveType.SelectedValue;
        //导出的文件路径
        string ExportPath;
        //导出的文件名称
        string FileName;
        ExportPath = Request.PhysicalApplicationPath + "报表/" + ReportName.AddDate() + "/";
        if (!Directory.Exists(ExportPath))
        {
            System.IO.Directory.CreateDirectory(Request.PhysicalApplicationPath + "报表/" + ReportName.AddDate() + "/");
        }
        FileName = "结班统计报表" + ReportName.AddDate();
        //FileName = Request.MapPath(".")+"\\报表\\" + ReportName.AddDate() + "\\" + FileName + "." + fileType;

        DiskFileDestinationOptions diskFile = new DiskFileDestinationOptions();
        //diskFile.DiskFileName = FileName;
        //导出为磁盘文件
        ExportOptions options = report.ExportOptions;
        options.ExportDestinationOptions = diskFile;
        options.ExportDestinationType = CrystalDecisions.Shared.ExportDestinationType.DiskFile;
        switch (DDLSaveType.SelectedItem.Value)
        {
            case "pdf":
                contenttype = "application/pdf";
                options.ExportFormatType = ExportFormatType.PortableDocFormat;
                break;
            case "doc":
                Response.ContentType = "application/ms-word";
                options.ExportFormatType = ExportFormatType.WordForWindows;
                break;
            case "xls":
                contenttype = "application/ms-excel";
                options.ExportFormatType = ExportFormatType.Excel;
                break;
            default:
                contenttype = "application/ms-excel";
                options.ExportFormatType = ExportFormatType.Excel;
                break;
        }

        FileName = FileName + "." + DDLSaveType.SelectedItem.Value;
        diskFile.DiskFileName = ExportPath + FileName;

        //导出操作    
        report.Export();
        if (MessageBox.Show(null, "数据已保存到服务器，是否下载到本地？", "信息提示：", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1,MessageBoxOptions.ServiceNotification) == DialogResult.Yes)
        {
            Response.Redirect("DownloadFile.aspx?FileName=" + diskFile.DiskFileName);
        }
        ReportLoad();
        ScriptManager.RegisterClientScriptBlock(UpdatePanel1, this.GetType(), null, "alert('报表已保存到服务器！')", true); 
    }

------解决方案--------------------