Got error when using the CCSprite subclass' object

Hello all,

I have a class which is a subclass of CCSprite. When I build, it caught the error. What’s wrong? :frowning:

E:/Working/android-ndk-r9c/toolchains/arm-linux-androideabi-4.6/prebuilt/windows-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld.exe: ./obj/local/armeabi/objs/cocos2dcpp_shared/__/__/Classes/ingame/GameplayScene.o: in function GameplayScene::shootBullet():jni/../../Classes/ingame/GameplayScene.cpp:95: error: undefined reference to 'CCBullet::create(int, char const*)'
/cygdrive/e/Working/android-ndk-r9c/build/core/build-binary.mk:579: recipe for target 'obj/local/armeabi/libcocos2dcpp.so' failed
make: Leaving directory '/cygdrive/e/Working/cocos2dx/cocos2dx/projects/Viking/proj.android'
E:/Working/android-ndk-r9c/toolchains/arm-linux-androideabi-4.6/prebuilt/windows-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld.exe: ./obj/local/armeabi/objs/cocos2dcpp_shared/__/__/Classes/ingame/GameplayScene.o: in function GameplayScene::init():jni/../../Classes/ingame/GameplayScene.cpp:34: error: undefined reference to 'CCBullet::create(int, char const*)'
collect2: ld returned 1 exit status
make: *** [obj/local/armeabi/libcocos2dcpp.so] Error 1