Mobile　edge　computing　(MEC)　offers　a　promising　technology　that　deploys　computing　resources　closer　to　mobile　devices　for　improving　performance.　Most　of　the　existing　studies　support　on-demand　remote　execution　of　the　computing　tasks　in　applications　through　program　transformation,　but　they　commonly　assume　that　mobile　devices　merely　resort　to　a　single　server　for　computation　offloading,　which　cannot　make　full　use　of　the　scattered　and　changeable　computing　resources.　Thus,　for　object-oriented　applications,　we　propose　a　novel　approach,　called　FUNOff,　to　support　the　dynamic　offloading　of　applications　in　MEC　at　the　function　granularity.　First,　we　extract　a　call　tree　via　code　analysis　and　locate　the　function　invocations　that　are　suitable　for　offloading.　Next,　we　refactor　the　code　of　related　object　functions　according　to　a　specific　program　structure.　Finally,　we　make　offloading　decisions　referring　to　the　context　at　runtime　and　send　function　invocations　to　multiple　remote　servers　for　execution.　We　evaluate　the　proposed　FUNOff　on　two　real-world　applications.　The　results　show　that,　compared　with　other　approaches,　FUNOff　better　supports　the　computation　offloading　of　object-oriented　applications　in　MEC,　which　reduces　the　response　time　by　10.7%-58.2%.