blocks|key|848037|text|在Android.mk文件中尝试执行以下操作：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|848038|LOCAL_LDLIBS+:=+-L$(SYSROOT)/usr/lib+-llog|code-block|syntax|javascript|848039|entityMap^0|1|A|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

Try the following in your <code>Android.mk</code> file:

<pre><code>LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
</code></pre>

blocks|key|1062403|text|您需要添加|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1062404|LOCAL_LDLIBS+:=+-llog|code-block|syntax|javascript|1062405|转到Android.mk|1062406|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

You need to add

<pre><code>LOCAL_LDLIBS := -llog
</code></pre>

to Android.mk

blocks|key|1062572|text|如果你使用Android+Studio和gradle，它会忽略Android.mk。将以下内容添加到您的build.gradle文件：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1062573|android+{
++++defaultConfig+{
++++++++ndk+{
++++++++++++moduleName+"your_module_name"
++++++++++++ldLibs+"log"
++++++++}
++++}
}|code-block|syntax|javascript|1062574|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If you use Android Studio and gradle, it ignores Android.mk. Add this to your build.gradle file:

<pre><code>android {
 defaultConfig {
 ndk {
 moduleName "your_module_name"
 ldLibs "log"
 }
 }
}
</code></pre>

blocks|key|848357|text|对于Android+Studio2.2和tools.build:gradle:2.2.0，使用CMake在CMakeLists.txt中添加或编辑行：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|848358|target_link_libraries(<your_library_name>+
++++++++++++++++++++++android+
++++++++++++++++++++++log)|code-block|syntax|javascript|848359|将日志库连接到您的日志库。|848360|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

For Android Studio 2.2 and tools.build:gradle:2.2.0 using CMake add or edit row in CMakeLists.txt:

<pre><code>target_link_libraries(&lt;your_library_name&gt; 
 android 
 log)
</code></pre>

Thats connecting log library to yours.

blocks|key|1062677|text|如果您升级到Android+Studio2.1，以上答案不起作用，需要使用ldLibs.add()加载lib，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1062678|android.ndk+{
++++moduleName+=+"[the_module_name]"
++++ldLibs.addAll(['android',+'log'])
}|code-block|syntax|javascript|1062679|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If you upgrade to Android Studio 2.1, above answers do not work, need use ldLibs.add() to load the lib as below:

<pre><code>android.ndk {
 moduleName = "[the_module_name]"
 ldLibs.addAll(['android', 'log'])
}
</code></pre>

blocks|key|848181|text|我们可以通过3种方式在Android中链接一个共享库。在以下3种情况下，应在Android.mk中添加上述行|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|848182|所以这里有三种方法。|848183|1.+LOCAL_LDLIBS+way
LOCAL_LDLIBS+:=+-llog|code-block|syntax|javascript|848184|出于某种原因，如果1不起作用(对我不起作用)，你可以尝试以下2种方法|848185|2.+LOCAL_LDFLAGS+way
LOCAL_LDFLAGS+:=+-llog

3.+LOCAL_SHARED_LIBRARIES+way
LOCAL_SHARED_LIBRARIES+%2B=+liblog|848186|当然，您还需要在C/H文件中包含#include+<android/log.h>。|848187|entityMap^0|12|A|0|0|0|0|0|G|O|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|X|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|Z|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|S|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|T|$]]

We can link a shared library in Android in 3 ways.
In below 3 cases, the lines mentioned should be added in <code>Android.mk</code>

So here are the three ways.

<pre><code>1. LOCAL_LDLIBS way
LOCAL_LDLIBS := -llog
</code></pre>

For some reason if 1 doesnt work(it did not work for me), You can try below 2 ways

<pre><code>2. LOCAL_LDFLAGS way
LOCAL_LDFLAGS := -llog

3. LOCAL_SHARED_LIBRARIES way
LOCAL_SHARED_LIBRARIES += liblog
</code></pre>

Of course you also need to include <code>#include &lt;android/log.h&gt;</code> in your C/H file.

blocks|key|1062474|text|是的，正如其他答案/评论所指定的那样，您确实需要添加：LOCAL_LDLIBS+:=+-llog，但是原始问题没有指定他是将JNI库用作：LOCAL_JNI_SHARED_LIBRARIES还是LOCAL_REQUIRED_MODULES。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1062475|我可以非常肯定地说，由于问题中的LOCAL_EXPORT_LDLIBS+:=+-llog，他将其用作：LOCAL_REQUIRED_MODULES……除非它是在编辑之后添加的。|1062476|如果使用LOCAL_REQUIRED_MODULES，共享库将安装在/system/lib中，而不是安装在apk中，因为它是必需的模块。因此，您需要添加LOCAL_LDLIBS+:=+-L$(SYSROOT)/usr/lib+-llog，而不仅仅是LOCAL_LDLIBS+:=+-llog，这样当构建系统构建和链接jni共享库时，它将在正确的位置拥有-llog定义，以便在$OUT/root/system/lib下构建。否则，您将继续得到相同的答案，即使您只添加了LOCAL_LDLIBS+:=+-llog。|1062477|所以，那些评论说不需要-L的人，另一个答案是正确的，他们在这种情况下实际上是不正确的。|1062478|entityMap^0|R|L|1X|Q|2P|M|0|G|S|1F|M|0|4|M|24|16|3G|L|4W|5|57|K|6H|L|0|B|2|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]|$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]|$9|14|A|15|B|C]|$9|16|A|17|B|C]|$9|18|A|19|B|C]|$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|1C|8|@$9|1D|A|1E|B|C]]|D|@]|E|$]]|$1|L|3|-4|5|6|7|1F|8|@]|D|@]|E|$]]]|M|$]]

Yes, you do need to add: <code>LOCAL_LDLIBS := -llog</code> as the other answers/comments have specified, however the original question did not specify if he use the jni library as: <code>LOCAL_JNI_SHARED_LIBRARIES</code> or as <code>LOCAL_REQUIRED_MODULES</code>. 

I can pretty much say for sure that he has it used it as: <code>LOCAL_REQUIRED_MODULES</code> because of the <code>LOCAL_EXPORT_LDLIBS := -llog</code> in the question... unless that was added after an edit.

If you use <code>LOCAL_REQUIRED_MODULES</code> the shared library is installed in /system/lib instead of into the apk, because it is a required module. Therefore you will need to add <code>LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog</code> instead of just <code>LOCAL_LDLIBS := -llog</code> so that when the build system is building &amp; linking the jni shared library, it will have the <code>-llog</code> definitions in the correct place, available to be built under <code>$OUT/root/system/lib</code>. Otherwise you will continue to get the same answer, even if you only add <code>LOCAL_LDLIBS := -llog</code>.

So, those who commented that the <code>-L</code> is not needed, and the other answer was correct, they were actually incorrect in this situation.

blocks|key|848060|text|添加|type|unstyled|depth|inlineStyleRanges|entityRanges|data|848061|LOCAL_SHARED_LIBRARIES:=+\
++++++++libbinder+++++++++++++++++++++++\
++++++++liblog++++++++++++++++++++++++++\|code-block|syntax|javascript|848062|转到Android.mk|848063|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Add 

<pre><code>LOCAL_SHARED_LIBRARIES:= \
 libbinder \
 liblog \
</code></pre>

to Android.mk

blocks|key|848280|text|这对我很有帮助：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|848281|Android.mk|848282|++++LOCAL_PATH+:=+$(call+my-dir)
include+$(CLEAR_VARS)

LOCAL_MODULE++++:=+nativeDemo
LOCAL_SRC_FILES+:=+main.cpp
LOCAL_LDLIBS+%2B=+-llog

include+$(BUILD_SHARED_LIBRARY)|code-block|syntax|javascript|848283|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

This helped for me:

Android.mk

<pre><code> LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)

LOCAL_MODULE := nativeDemo
LOCAL_SRC_FILES := main.cpp
LOCAL_LDLIBS += -llog

include $(BUILD_SHARED_LIBRARY)
</code></pre>

blocks|key|1062713|text|-DCMAKE_CXX_FLAGS="-llog“帮助我|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1062714|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

-DCMAKE_CXX_FLAGS="-llog" helps me

blocks|key|1062736|text|在Android.mk中添加LOCAL_SHARED_LIBRARIES:=+liblog可以解决我的问题。这是因为__android_log_print是在libLog中定义的|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1062737|entityMap^0|E|V|1M|J|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

add
<code>LOCAL_SHARED_LIBRARIES:= liblog</code>
to Android.mk can solve my isuue.
This is because the <code>__android_log_print</code> is defined in libLog

What is wrong with my make file?

Android.mk

<pre><code>LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := foo
LOCAL_SRC_FILES := foo.c
LOCAL_EXPORT_LDLIBS := -llog
include $(BUILD_SHARED_LIBRARY)
</code></pre>

foo.c

<pre><code>#include &lt;string.h&gt;
#include &lt;jni.h&gt;
#include &lt;android/log.h&gt;

#define LOG_TAG "foo"
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)

void test() {
 LOGI("test");
}
</code></pre>

ndk-build

<pre><code>foo.c:9: undefined reference to `__android_log_print'
</code></pre>

undefined reference to `__android_log_print'

Android Studio

Android

我的make文件有什么问题？Android.mkLOCAL_PATH := $(call my-dir)include $(CLEAR_VARS)LOCAL_MODULE := fooLOCAL_SRC_FILES := foo.cLOCAL_EXPORT_LDLIBS := -lloginclude $(BUILD_SHARED_LIBRARY)foo.c#include <string.

问未定义对`__android_log_print‘的引用
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问未定义对`__android_log_print‘的引用EN

回答 11

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问未定义对`__android_log_print‘的引用
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