class Program
    {
        static void Main(string[] args)
        {
            string fileName = @"..\..\Documents\Myppt7.pptx";
            foreach (string s in GetAllExternalHyperlinksInPresentation(fileName))
                Console.WriteLine(s);
        }
        // Returns all the external hyperlinks in the slides of a presentation.
        public static IEnumerable GetAllExternalHyperlinksInPresentation(string fileName)
        {
            // Declare a list of strings.
            List ret = new List();

            // Open the presentation file as read-only.
            using (PresentationDocument document = PresentationDocument.Open(fileName, false))
            {
                // Iterate through all the slide parts in the presentation part.
                foreach (SlidePart slidePart in document.PresentationPart.SlideParts)
                {
                    IEnumerable links = slidePart.Slide.Descendants();

                    // Iterate through all the links in the slide part.
                    foreach (Drawing.HyperlinkType link in links)
                    {
                        // Iterate through all the external relationships in the slide part. 
                        foreach (HyperlinkRelationship relation in slidePart.HyperlinkRelationships)
                        {
                            // If the relationship ID matches the link ID…
                            if (relation.Id.Equals(link.Id))
                            {
                                // Add the URI of the external relationship to the list of strings.
                                ret.Add(relation.Uri.AbsoluteUri);
                            }
                        }
                    }
                }
            }

            // Return the list of strings.
            return ret;
        }

    }

class Program
    {
        static void Main(string[] args)
        {
            string fileName = @"..\..\Documents\Myppt7.pptx";
            foreach (string s in GetAllExternalHyperlinksInPresentation(fileName))
                Console.WriteLine(s);
            Console.ReadLine();
        }
        // Returns all the external hyperlinks in the slides of a presentation.
        public static IEnumerable GetAllExternalHyperlinksInPresentation(string fileName)
        {
            // Declare a list of strings.
            List ret = new List();

            Presentation pres = new Presentation(fileName, FileFormat.Pptx2010);

            //Get the hyperlinks from presentation slides
            foreach (ISlide slide in pres.Slides)
            {
                foreach (IAutoShape shape in slide.Shapes)
                {
                    ret.Add(shape.TextFrame.TextRange.ClickAction.Address);
                }
            }
            return ret;
        }
    }