combine

Thanks for the information, what does the below code does ?? can u please explain.in detail
docDst.SetCahce(localFolder.Path + "/cache.dat");
PDFImportCtx ctx = docDst.ImportStart(docSrc);

also does purchasing Direct Support entitles for custom development help ?

SetCache --> set cache file to PDF to save some temporary data, compressed images and so on .. used while manipulating the PDF
This cache file can be deleted after the modifications has been saved to the document.

ImportStart --> Start import operations, (like import page from src document), the returned object should be maintened until all pages are imported and ImportContext.Destroy() invoked.

Direct support is about the use of RadaeePDF library and not custom development.
With direct support you will receive information about how to use our API, workaround, integration.
We can’t provide you deep information about Windows UI/UX outside the rendering engine and it’s own methods.

ie.: developing a multi-file selector is outside our standard support as it’s a really custom interface.

Thanks for the information, in the sample there is a way to get stream from selected storage file & open it as PDF doc but is there an alternative way to get stream out of PDF doc back ??

i have also just tried the snippet given & i got an exception , i am attaching a screenshot please see that.

get stream out of PDF doc back -> no, you need to save it back first.

For the exception: make sure that your file is located in a folder where you have the permission to read/write.
in the example, the files are located in the app's local data folder
Windows.Storage.StorageFolder localFolder = Windows.Storage.ApplicationData.Current.LocalFolder;

i have copied the 2 files src.pdf & dst.pdf to app data folder as you said, is it not the correct way to do ??,

ok i shall save the resultant doc, after that can i use doc.createstream method to copy the doc stream to storagefile ? or is there any other alternative??

Thanks.