Document doc = application.ActiveUIDocument.Document;
FilteredElementCollector collector = new FilteredElementCollector(doc);
ICollection<Element> collection = collector.OfClass(typeof(Autodesk.Revit.DB.View)).ToElements();
foreach (Element element in collection)

{
    Autodesk.Revit.DB.View view = element as Autodesk.Revit.DB.View;
    if (null != view)
    {
        string messageInfo = "BoundingBoxUV : ";
        messageInfo += "\nView name : " + view.Name;
        BoundingBoxUV boundingBox = view.Outline;
        // Get max bounding box
        UV max = boundingBox.Max;
        messageInfo += "\nMax boundingbox : (" + max.U + "," + max.V + ")";
        // Get min bounding box
        UV min = boundingBox.Min;
        messageInfo += "\nMin boundingbox : (" + min.U + "," + min.V + ")";
        // Get bounds,
        // Use 0 for Min and 1 for Max
        UV bound = boundingBox.get_Bounds(0);
        messageInfo += "\nBoundingbox bounds : (" + bound.U + "," + bound.V + ")";
        TaskDialog.Show("Revit",messageInfo);
    }
}

Dim doc As Document = application.ActiveUIDocument.Document
Dim collector As New FilteredElementCollector(doc)
Dim collection As ICollection(Of Element) = collector.OfClass(GetType(Autodesk.Revit.DB.View)).ToElements()
For Each element As Element In collection

    Dim view As Autodesk.Revit.DB.View = TryCast(element, Autodesk.Revit.DB.View)
    If view IsNot Nothing Then
        Dim messageInfo As String = "BoundingBoxUV : "
        messageInfo += vbLf & "View name : " + view.Name
        Dim boundingBox As BoundingBoxUV = view.Outline
        ' Get max bounding box
        Dim max As UV = boundingBox.Max
        messageInfo += vbLf & "Max boundingbox : (" + max.U + "," + max.V + ")"
        ' Get min bounding box
        Dim min As UV = boundingBox.Min
        messageInfo += vbLf & "Min boundingbox : (" + min.U + "," + min.V + ")"
        ' Get bounds,
        ' Use 0 for Min and 1 for Max
        Dim bound As UV = boundingBox.Bounds(0)
        messageInfo += vbLf & "Boundingbox bounds : (" + bound.U + "," + bound.V + ")"
        TaskDialog.Show("Revit", messageInfo)
    End If
Next