Merging XPS documents causing memory leak

Question

I am using the following code to merge xps documents.   I do this in a web app.  The code works fine without a problem, however I get a memory leak.  With every merge more handles are created and more Heap 2 memory is allocated and will not be taken back, even if I force a garbage collection. ie. GC.Collect( 2 ).

 

This memory is never freed and eventually the web site runs into SystemOutOfMemory.

 

Can anyone see something I am doing wrong?  Or if they have encountered this problem before, know of a work around?

 

Code Block

Package oPackage = null;

XpsDocument oXpsDocument = null;

try {

// New XPS package

oPackage = Package.Open( sTempFilename, FileMode.Create );

oXpsDocument = new XpsDocument( oPackage, CompressionOption.SuperFast );

FixedDocumentSequence oFixedDocumentSequence = new FixedDocumentSequence();

// Read in old

foreach( string sXpsDocument in sXPSFiles ) {

XpsDocument oSourceDocument = new XpsDocument( sXpsDocument, FileAccess.Read );

FixedDocumentSequence oOldFixedDocumentSequence = oSourceDocument.GetFixedDocumentSequence();

foreach( DocumentReference oDocumentReference in oOldFixedDocumentSequence.References ) {

DocumentReference oNewDocReference = new DocumentReference();

( oNewDocReference as IUriContext ).BaseUri = ( oDocumentReference as IUriContext ).BaseUri;

oNewDocReference.Source = oDocumentReference.Source;

oFixedDocumentSequence.References.Add( oNewDocReference );

oNewDocReference = null;

}

oSourceDocument.Close();

oSourceDocument = null;

}

XpsDocumentWriter oXpsDocumentWriter = XpsDocument.CreateXpsDocumentWriter( oXpsDocument );

//oXpsDocumentWriter.WriteAsync( oFixedDocumentSequence );

oXpsDocumentWriter.Write( oFixedDocumentSequence );

 

oXpsDocument.Close();

oPackage.Close();

 

oFixedDocumentSequence = null;

oXpsDocumentWriter = null;

} catch( Exception ex ) {

// Output exception

} finally {

if( oXpsDocument != null ) {

oXpsDocument.Close();

oXpsDocument = null;

}

if( oPackage != null ) {

oPackage.Close();

oPackage = null;

}

}

 

 

Answer 1

This is a bug in the FixedDocumentSequence. The only *work-around* currently exists is to call UpdateLayout() to at least *one* fixed page...

in your case:

...
FixedPage page = oOldFixedDocumentSequence.DocumentPaginator.GetPage(0).Visual as FixedPage;
page.UpdateLayout();
...

and it should work... old question, but in case someone is running into the same problem... (c;

-Jo