Undefined symbols for architecture x86_64:
"OBJC_CLASS$_FlutterViewController", referenced from:
type metadata for O2Platform.O2FlutterViewController in O2FlutterViewController.o
"OBJC_METACLASS$_FlutterViewController", referenced from:
OBJC_METACLASS$__TtC10O2Platform23O2FlutterViewController in O2FlutterViewController.o
"OBJC_CLASS$_FlutterAppDelegate", referenced from:
type metadata for O2Platform.AppDelegate in AppDelegate.o
"OBJC_CLASS$_FlutterMethodChannel", referenced from:
objc-class-ref in O2FlutterViewController.o
"OBJC_METACLASS$_FlutterAppDelegate", referenced from:
OBJC_METACLASS$__TtC10O2Platform11AppDelegate in AppDelegate.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
能不能帮忙看一下?