iphone GData spreadsheet unrecognized selector

I've used the GData spreadsheets code for MAC to write a corresponding iPhone version (the same code), but I get a exception thrown: [GDataEntryBase worksheetsFeedURL]: unrecognized selector sent to instance ... It appears to me that when fetchi开发者_StackOverflow中文版ng the entries from the spreadsheet feed, I got a array of GDataEntryBase (iPhone version) instead of GDataEntrySpreadsheet. Any help will be highly appreciated!

Thank you.

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The base class is created when the needed subclasses aren't compiled and linked into the application.

Be sure the -ObjC linker flag is set for your project, and that -DGDATA_REQUIRE_SERVICE_INCLUDES=1 and -DGDATA_INCLUDE_SPREADSHEET_SERVICE=1 are defined for the target that includes the spreadsheet classes. ( in GData.xcodeproj > Build Settings > Other Linker Flags )

These are discussed on the BuildingTheLibrary wiki page for the project.