Visualizador de arquivos PPTM para .NET

string output = System.IO.Path.GetTempPath() + Guid.NewGuid().ToString() + ".html";

// instantiate a Presentation object & load the PPTM file
using (var presentation = new Aspose.Slides.Presentation("templatepptm"))
{
    // create HTML export controller
    var controller = new Aspose.Slides.Export.ResponsiveHtmlController();
    // create an instance of HtmlOptions and set HtmlFormatter property
    var htmlOptions = new Aspose.Slides.Export.HtmlOptions 
    { 
        HtmlFormatter = Aspose.Slides.Export.HtmlFormatter.CreateCustomFormatter(controller) 
    };

    // save the presentation in HTML
    presentation.Save(output, Aspose.Slides.Export.SaveFormat.Html, htmlOptions);
}
// load HTML to view the presentation content
System.Diagnostics.Process.Start(output);