// instantiate a Presentation Object
Presentation pres = new Presentation();

// Get first slide
ISlide sld = pres.getSlides().get_Item(0);

// Add an AutoShape of Rectangle type
IAutoShape ashp = sld.getShapes().addAutoShape(ShapeType.Rectangle,
        150, 75, 150, 50);

// Add TextFrame to the Rectangle
ashp.addTextFrame("Aspose TextBox");

// Disable shape fill in case we want to get shadow of text.
ashp.getFillFormat().setFillType(FillType.NoFill);

// Add outer shadow and set all necessary parameters
OuterShadow shadow = new OuterShadow();
ashp.getEffectFormat().setOuterShadowEffect(shadow);
shadow.setBlurRadius(4.0);
shadow.setDirection(45);
shadow.setDistance(3);
shadow.setRectangleAlign(RectangleAlignment.TopLeft);
shadow.getShadowColor().setPresetColor(PresetColor.Black);