设置Library的输出目录
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY
P
R
O
J
E
C
T
S
O
U
R
C
E
D
I
R
/
j
n
i
L
i
b
s
/
{PROJECT_SOURCE_DIR}/jniLibs/
PROJECTSOURCEDIR/jniLibs/{ANDROID_ABI})
设置函数的默认导出可见性
set(CMAKE_C_VISIBILITY_PRESET hidden)
set(CMAKE_CXX_VISIBILITY_PRESET hidden)