I have get label of gif file successfully.how to get pdf format.I have read the guide about labelimageformat several times.It says:
"Label print method code that the Labels are to be generated for EPL2 formatted Labels use EPL, for SPL formatted Labels use SPL, for ZPL formatted Labels use ZPL and for image formats use GIF, for Star Printer format formatted Labels use STARPL.
For shipments without return service the valid value is GIF, ZPL, EPL and SPL. For shipments with PRL return service, the valid values are EPL, ZPL, SPL, STARPL and GIF."