Android JNI開發系列(四)經過C語言打印日誌

Android Studio 經過C語言打印日誌

• 引用Log.h 包
• 宏定義

//
// Created by Peng Cai on 2018/9/29.
//
#include <jni.h>
#include <android/log.h>

extern "C"  // C 編譯器編譯個人代碼

#define LOGTAG "HELLO"

#define LOGE (...)__android_log_print(ANDROID_LOG_INFO,LOGTAG,__VA_ARGS__);


JNIEXPORT jstring
JNICALL
Java_org_professor_jni_MainActivity_stringFromJNI(JNIEnv *env, jobject instance) {

    return (*env)->NewStringUTF(env, "I am form c");
}

JNIEXPORT jint JNICALL
Java_org_professor_jni_MainActivity_add(JNIEnv *env, jobject instance, jint a, jint b) {

    char *str = "Hello world";
//    __android_log_print(ANDROID_LOG_INFO,"HELLO","%d",a);
//    __android_log_print(ANDROID_LOG_ERROR,"HELLO","%d",b);
//    __android_log_print(ANDROID_LOG_WARN,"HELLO","%d",a+b);
//    __android_log_print(ANDROID_LOG_WARN,"HELLO","%s",str);
    LOGE("b=%d", b);
    return a + b;
}