This sample project demonstrates how to show report in the viewer. First of all, use Load method to load a report file:

 private void buttonControl_Click(object sender, EventArgs e)
{
	var report = new StiReport();
	report.Load(@"Reports\SimpleList.mrt");
	report.Render();
	stiViewerControl1.Report = report;
}

...

Next, use Show method to show report in the viewer:

...

private void buttonDialog_Click(object sender, EventArgs e)
{
	var report = new StiReport();
	report.Load(@"Reports\SimpleList.mrt");
	report.Show();
	//report.ShowWithRibbonGUI();
}

Auf dem Screenshot unten Sie können das Ergebnis des Beispiel-Codes ansehen: