1、执行ndk-build 提示error: request for member 'FindClass' in something not a structure or union
/Users/lvxiangan/Workspace/Android_Studio/NDK/app/src/main/jni/test.c:33:30: error: member reference base type 'JNIEnv' (aka 'const struct JNINativeInterface *') is not a structure or union
jclass native_class = env->GetObjectClass(contextObject);
~~~^ ~~~~~~~~~~~~~~
/Users/lvxiangan/Workspace/Android_Studio/NDK/app/src/main/jni/test.c:34:26: error: member reference base type 'JNIEnv' (aka 'const struct JNINativeInterface *') is not a
structure or union
jmethodID pm_id = env->GetMethodID(native_class, "getPackageManager", "()Landroid/content/pm/PackageManager;");
~~~^ ~~~~~~~~~~~
/Users/lvxiangan/Workspace/Android_Studio/NDK/app/src/main/jni/test.c:35:25: error: member reference base type 'JNIEnv' (aka 'const struct JNINativeInterface *') is not a
structure or union
jobject pm_obj = env->CallObjectMethod(contextObject, pm_id);
~~~^ ~~~~~~~~~~~~~~~~
/Users/lvxiangan/Workspace/Android_Studio/NDK/app/src/main/jni/test.c:36:26: error: member reference base type 'JNIEnv' (aka 'const struct JNINativeInterface *') is not a
structure or union
错误原因：env变量在C和C++ 语法表达不一致引起。
C++ ：env->FindClass("java/lang/String")
C语言：(*env)->FindClass(env, "java/lang/String")
2、No rule to make target needed by *.o
make: *** No rule to make target `x x x/xxxx/xxx/xx.c', needed by `x x x/xxxx/xxx/xx.c.o'. Stop.
错误原因：Android.mk没有修改文件后缀名，如原来是LOCAL_SRC_FILES := test.c，修改成
step1）LOCAL_SRC_FILES := test.cpp
step2）删除/app/src/main/obj/local 文件夹
3、返回一个字符串报错： error: too many arguments to function call, expected single argument 'bytes', have 2 arguments
return env->NewStringUTF(env,"This is my first NDK Application");
~~~~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/lvxiangan/ProgramFiles/AndroidStudio/Sdk/ndk-bundle/sysroot/usr/include/jni.h:840:5: note: 'NewStringUTF' declared here
jstring NewStringUTF(const char* bytes)
^
1 error generated.
