A dashboard renders and exports to documents and data formats just like a report.

Load, then export.
var report = StiReport.CreateNewDashboard();
report.Load("Dashboards\\DashboardChristmas.mrt");

var stream = new FileStream("Dashboard.pdf", FileMode.Create);
report.ExportDocument(StiExportFormat.Pdf, stream);   // Excel, Image, ...

How it works. The dashboard is rendered and serialized to the chosen format in one call, ready to be saved or sent.
На скриншоте ниже Вы можете увидеть результат выполнения данного кода:

Exporting a Dashboard