private void GetRunType(Stairs stairs)
{
    ICollection<ElementId> runIds = stairs.GetStairsRuns();

    ElementId firstRunId = runIds.First();

    StairsRun firstRun = stairs.Document.GetElement(firstRunId) as StairsRun;
    if (null != firstRun)
    {
        StairsRunType runType = stairs.Document.GetElement(firstRun.GetTypeId()) as StairsRunType;
        // Format landing type info for display
        string info = "Stairs Run Type:  " + runType.Name;
        info += "\nRiser Thickness:  " + runType.RiserThickness;
        info += "\nTread Thickness:  " + runType.TreadThickness;

        TaskDialog.Show("Revit", info);
    }
}

Private Sub GetRunType(stairs As Stairs)
    Dim runIds As ICollection(Of ElementId) = stairs.GetStairsRuns()

    Dim firstRunId As ElementId = runIds.First()

    Dim firstRun As StairsRun = TryCast(stairs.Document.GetElement(firstRunId), StairsRun)
    If firstRun IsNot Nothing Then
        Dim runType As StairsRunType = TryCast(stairs.Document.GetElement(firstRun.GetTypeId()), StairsRunType)
        ' Format landing type info for display
        Dim info As String = "Stairs Run Type:  " + runType.Name
        info += vbLf & "Riser Thickness:  " + runType.RiserThickness
        info += vbLf & "Tread Thickness:  " + runType.TreadThickness

        TaskDialog.Show("Revit", info)
    End If
End Sub