PPT导出为图片

使用Aspose组件导出

Aspose有Aspose.Slides.dll，可以无需安装office，进行读写PPT文件。

Aspose可能通过Aspose.Slides.NET安装

简单的导出图片demo，如下：

     internal class PptToImagesConverter
     {
         private const string ImageExtension = ".png";
         public bool ConvertToImages(string pptFile, string exportImagesFolder)
         {
             using (Presentation pres = new Presentation(pptFile))
             {
                 int desiredX = ;
                 int desiredY = ;

                 float scaleX = (float)(1.0 / pres.SlideSize.Size.Width) * desiredX;
                 float scaleY = (float)(1.0 / pres.SlideSize.Size.Height) * desiredY;

                 foreach (ISlide sld in pres.Slides)
                 {
                     Bitmap bmp = sld.GetThumbnail(scaleX, scaleY);

                     string slidePath = Path.Combine(exportImagesFolder,$"Slide_{sld.SlideNumber}.{ImageExtension}");
                     bmp.Save(slidePath, System.Drawing.Imaging.ImageFormat.Png);
                 }
             }

             return true;
         }
     }

注：以上途径是没有购买过的dll，生成的图片会有水印。使用正版购买的，应该不会有问题。

使用Interop.PowerPoint导出

也是在Nuget中搜索并安装：

另，通过Presentations.Open("c:\test.pptx::PASSWORD::")可以解密PPT，从而导出图片。

     internal class PptToImagesConverter1
     {
         private const string PASSWORD_MARK = "::PASSWORD::";
         private const string ImageExtension = ".png";
         public bool ConvertToImages(string pptFile, string exportImagesFolder)
         {
             var tempPpt = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + Path.GetExtension(pptFile));
             File.Copy(pptFile, tempPpt);
             Microsoft.Office.Interop.PowerPoint.Application app = new Microsoft.Office.Interop.PowerPoint.Application();
             Microsoft.Office.Interop.PowerPoint.Presentation presentation = app.Presentations.Open(tempPpt + PASSWORD_MARK, MsoTriState.msoTrue, MsoTriState.msoFalse, MsoTriState.msoFalse);
             int desiredX = ;
             int desiredY = ;
             var slides = ((Microsoft.Office.Interop.PowerPoint.Presentation)presentation).Slides.Cast<Microsoft.Office.Interop.PowerPoint.Slide>().ToList();
             Parallel.ForEach(slides, slide =>
             {
                 string slidePath = Path.Combine(exportImagesFolder, "Slide-" + slide.SlideIndex + ImageExtension);
                 slide.Export(slidePath, ImageExtension, desiredX, desiredY);
             });
             return true;
         }
     }