@saleembaig,
Welcome to our community! Thank you for your request.
You can open a PPTX file from an URL or stream as below:
MemoryStream presentationStream;
using (var client = new System.Net.WebClient())
{
var presentationData = client.DownloadData(pptxUrl);
presentationStream = new MemoryStream(presentationData);
}
presentationStream.Seek(0, SeekOrigin.Begin);
var presentation = new Presentation(presentationStream);
You can save a presentation into Stream or byte array as below:
var memoryStream = new MemoryStream();
presentation.Save(memoryStream, SaveFormat.Pptx);
memoryStream.Seek(0, SeekOrigin.Begin);
var byteArray = new byte[memoryStream.Length];
memoryStream.Read(byteArray, 0, (int)memoryStream.Length);