How to refresh crystal report in visual studio 2019

Question

I am using visual studio 2019, while displaying crystal report, i am facing problem that report is not refreshing but showing correctly. It only refreshes when I refresh it from report viewer refresh button during runtime. My code is here 

private void PrptViewer_Loaded(object sender, RoutedEventArgs e)
{
    PatientReport p = new PatientReport();
    p.Load(@"PatientReport.rpt");
    PrptViewer.ViewerCore.ReportSource = p;

}

If anyone can help me in this regard.