Visio.Application vsdApp = null;
            Visio.Document vsdDoc = null;

            //Create Visio Application Object
            vsdApp = Application;

            //Make Visio Application Invisible
            vsdApp.Visible = false;

            //Create a document object and load a diagram
            vsdDoc = vsdApp.Documents.Open("Add Shapes.vdx");

            Visio.Documents visioDocs = this.Application.Documents;
            Visio.Document visioStencil = visioDocs.OpenEx("Basic Shapes.vss",
                (short)Microsoft.Office.Interop.Visio.VisOpenSaveArgs.visOpenDocked);

            Visio.Page visioPage = this.Application.ActivePage;

            Visio.Master visioRectMaster = visioStencil.Masters.get_ItemU(@"Rectangle");
            Visio.Shape visioRectShape = visioPage.Drop(visioRectMaster, 4.25, 5.5);
            visioRectShape.Text = @"Rectangle text.";

            Visio.Master visioStarMaster = visioStencil.Masters.get_ItemU(@"Star 7");
            Visio.Shape visioStarShape = visioPage.Drop(visioStarMaster, 2.0, 5.5);
            visioStarShape.Text = @"Star text.";

            Visio.Master visioHexagonMaster = visioStencil.Masters.get_ItemU(@"Hexagon");
            Visio.Shape visioHexagonShape = visioPage.Drop(visioHexagonMaster, 7.0, 5.5);
            visioHexagonShape.Text = @"Hexagon text.";

 // Load masters from any existing diagram, stencil or template
            // and add in the new diagram
            string visioStencil = "Add Shapes.vdx";

            //Names of the masters present in the stencil
            string rectangleMaster = @"Rectangle";

            int pageNumber = 0;
            double width = 2, height = 2, pinX = 4.25, pinY = 9.5;

            // Create a new diagram
            Diagram diagram = new Diagram(visioStencil);

            //Add a new rectangle shape
            long rectangleId = diagram.AddShape(
                pinX, pinY, width, height, rectangleMaster, pageNumber);

            //Save the diagram
            diagram.Save("Add Shapes.vdx", SaveFileFormat.VDX);