Xcode真机调试出现的错误~

错误信息如下：
Undefined symbols for architecture armv7:
"_xdSendMessage", referenced from:
_Herald_xdSendMessage_m2534056276 in Bulk_Assembly-CSharp-firstpass_0.o
(maybe you meant: _Herald_xdSendMessage_m2534056276)
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)