How I can change the text and Image in cdr file using c#.net

I had tried this above by following code, but it is not working,

CorelDRAW.Application cdr = new CorelDRAW.Application();
            cdr.Visible = false;
            cdr.OpenDocument(@"B:\\a1.cdr", 1);
            foreach (Shape s in cdr.ActiveSelectionRange)
            {
                if (s.Type != cdrShapeType.cdrTextShape) continue;
                s.Text.Replace("Hi","new Hi",false);
            }

cdr.Quit();

after cdr.ActiveSelectionRange it goes out of loop, not atleast once it goes into the loop, what should I do, and also please provide the information about how to change the Image in the file.

Thank you