My apologies I found the method: public override string[] FilesDropped (NSOutlineView outlineView, NSUrl dropDestination, NSArray items) -- View this message in context: http://mono.1490590.n4.nabble.com/NSOutlineViewDataSource-missing-a-method-tp3593851p3594089.html Sent from the Mono - OSX mailing list archive at Nabble.com.