This demo uses the DevExpress Presentation API to merge multiple presentations into a single file. You can merge predefined sample files or supply your own documents. To do the latter, select Upload a File in the file selection drop-down menu and upload files one at a time.
Use the Merge and Save as... dropdown button to select the output format, merge presentations, and download the result.
Sample document
Sample_first.pptx
Sample_second.pptx
using DevExpress.Docs.Presentation;
Stream MergePresentations(List<Stream> inputStreams, DocumentFormat targetFormat, bool pdfOutput) {
var outputStream = new MemoryStream();
if(inputStreams.Count > 0) {
using var presentation = new Presentation(inputStreams[0]);
for(int i = 1; i < inputStreams.Count; i++) {
var inputStream = inputStreams[i];
using var tempPresentation = new Presentation(inputStream);
foreach(var slide in tempPresentation.Slides)
presentation.Slides.Add(slide);
}
if(pdfOutput)
presentation.ExportToPdf(outputStream);
else
presentation.SaveDocument(outputStream, targetFormat);
}
outputStream.Position = 0;
return outputStream;
}