水晶报表导出为 pdf，报表在首次导出后不会应用新参数

我实现了一个将水晶报告导出为pdf的循环。这个想法是用它的链接实例化初始报告，然后在循环中应用参数，然后再导出为 PDF（所以我每条记录得到一个 pdf），但报告不断导出带有第一个循环执行数据的 pdf。如何强制它在应用新参数后刷新其数据？

示例代码：

ReportDocument reportDoc=new ReportDocument();
reportDoc.Load("c:''reportx.rpt");
ConnectionInfo cinfo = FunctionLibrary.getCrystalConection();
foreach (Table table in reportDoc.Database.Tables)
{
    table.LogOnInfo.ConnectionInfo = cinfo;
    table.ApplyLogOnInfo(table.LogOnInfo);
}
string[] docnumbers=new[]{"1","2","3","4"};
for(int i=0;i<docnumbers.Lenght; i++)
{
    report.SetParameterValue(0, docnumbers[i]);
    report.Refresh();
    DiskFileDestinationOptions CrDiskFileDestinationOptions = new DiskFileDestinationOptions();
    PdfRtfWordFormatOptions CrFormatTypeOptions = new PdfRtfWordFormatOptions();
    CrDiskFileDestinationOptions.DiskFileName = "C:''generatedpdf " + docnumbers[i] + ".pdf";
    ExportOptions CrExportOptions = reportDoc.ExportOptions;
    {
        CrExportOptions.ExportDestinationType = ExportDestinationType.DiskFile;
        CrExportOptions.ExportFormatType = ExportFormatType.PortableDocFormat;
        CrExportOptions.DestinationOptions = CrDiskFileDestinationOptions;
        CrExportOptions.FormatOptions = CrFormatTypeOptions;
    }
    reportDoc.Export();
}
reportDoc.Close();