win64位操作系统reportView显示怎么变成这样？

测试代码如下：
 DataTable dt = new DataTable();
            string rptFile = System.Windows.Forms.Application.StartupPath + @"\ZTO.rdlc";
            reportViewer1.LocalReport.ReportPath = rptFile;

            ReportDataSource source = new ReportDataSource("DataSet1", dt);
            reportViewer1.LocalReport.DataSources.Clear();
            reportViewer1.LocalReport.DataSources.Add(source);

            reportViewer1.SetDisplayMode(Microsoft.Reporting.WinForms.DisplayMode.PrintLayout);
            this.reportViewer1.ZoomMode = Microsoft.Reporting.WinForms.ZoomMode.Percent;
            this.reportViewer1.ZoomPercent = 100;
            reportViewer1.RefreshReport();

显示结果

它的视图显示超过的窗体大小。怎么回事？ 求解 64位 ReportView

补充：.NET技术 ,  C#