Log print "Go" in the-----Jni of Android

This article was reproduced from: http://blog.csdn.net/zengraoli/article/details/11644815

1. import Log header file

In the. c/. cpp file that you are using

Import Log.h Header File

#include <android/log.h>

2. In the ANDROID.MK

Plus

Local_ldlibs: =-llog

Notice there's a line in Android.mk. Include $ (clear_vars)

Local_ldlibs: =-llog must be put behind it to be used,

Otherwise the equivalent is not written.

3. Define the Log function

Define a global variable, and then define some output log functions:

[CPP]View Plaincopyprint?

2. #define TAG "Mydemo-jni"//This is the identity of the custom log
4. #define LOGD (...) __android_log_print (Android_log_debug,tag, __va_args__)//define LOGD type
6. #define Logi (...) __android_log_print (Android_log_info,tag, __va_args__)//define Logi type
8. #define LOGW (...) __android_log_print (Android_log_warn,tag, __va_args__)//define LOGW type
10. #define LOGE (...) __android_log_print (Android_log_error,tag, __va_args__)//define LOGE type
12. #define LOGF (...) __android_log_print (Android_log_fatal,tag, __va_args__)//define LOGF type

functions defined in the preceding code

corresponding to the Java code in Android, respectively.

LOG.D (), LOG.I (), LOG.W (), LOG.E (), LOG.F () and other methods.

4. For example

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2. #include <jni.h>
4. #include <string.h>
6. #include <android/log.h>
10. #define TAG "Myhello-jni-test"//This is the identity of the custom log
12. #define LOGD (...) __android_log_print (android_log_debug,tag,__va_args__)//define LOGD type
16. extern "C" {
18. Jniexport jstring jnicall Java_com_snail_helloworld_mainactivity_myhello (jnienv * env, jobject obj);
20. };
24. Jniexport jstring jnicall Java_com_snail_helloworld_mainactivity_myhello (jnienv * env, Jobject obj)
26. {
28. int i = 0;
30. LOGD ("########## i =%d", i);
32. return Env->newstringutf ("Hello from CPP");
34. }

Android.mk

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1. Local_path: = $ (call My-dir)
3. Include $ (clear_vars)
5. Local_module: = Hello
6. Local_src_files: = Hello.cpp
7. Local_ldlibs: =-llog
9. Include $ (build_shared_library)

Log print "Go" in the-----Jni of Android