this application was created using the trial version of the xtrareports 解决方法

XtraReport3 xtraReport = new XtraReport3();
var mlc = sp.tiaoma.ToList();
xtraReport.DataSource = mlc;ReportPrintTool tool = new ReportPrintTool(xtraReport);//操作要显示什么按钮
tool.PrintingSystem.SetCommandVisibility(new PrintingSystemCommand[]{
PrintingSystemCommand.Open,
PrintingSystemCommand.Save,
PrintingSystemCommand.ClosePreview,
PrintingSystemCommand.Customize,
PrintingSystemCommand.SendCsv,
PrintingSystemCommand.SendFile,
PrintingSystemCommand.SendGraphic,
PrintingSystemCommand.SendMht,
PrintingSystemCommand.SendPdf,
PrintingSystemCommand.SendRtf,
PrintingSystemCommand.SendTxt,
PrintingSystemCommand.SendXls
}, CommandVisibility.None);
tool.ShowPreview();