Fast Incremental Saving to a StorageFile in Windows Store apps

Q: I open a PDFDoc from a StorageFile (new PDFDoc(StorageFile file, string path)), edit it with an annotation, and then try to save it. If the file is big, it can take more than a minute. How can I make saving faster.

If you opened using a path or any other way, this save function will not work. (Note, for fast saving to paths, simply use the same path as when you opened).

The function PDFDoc.SaveAsync(file, pdftron.SDF.SDFDocSaveOptions.e_incremental) should really only be used when performing a SaveAs type operation. Though after this function has been called, you can use PDFDoc.SaveAsync(pdftron.SDF.SDFDocSaveOptions.e_incremental) and it will save incrementally to the file you picked when you saved.
A: In our latest Release (6.1.1.21853) we improved our saving performance. Now, If you have opened the document using an IRandomAccessStream (with Read and Write permissions) you can call PDFDoc.SaveAsync(pdftron.SDF.SDFDocSaveOptions.e_incremental) and it will perform an incremental save to the stream you opened the doc with. This should give you very fast saving.