Android应用如何监听自己是否被卸载及卸载反馈功能的实现

一个应用被用户卸载肯定是有理由的，而开发者却未必能得知这一重要的理由，毕竟用户很少会主动反馈建议，多半就是用得不爽就卸，如果能在被卸载后获取到用户的一些反馈，那对开发者进一步改进应用是非常有利的。目前据我所知，国内的Android应用中实现这一功能的只有360手机卫士、360平板卫士，那么如何实现这一功能的？

　　我们可以把实现卸载反馈的问题转化为监听自己是否被卸载，只有得知自己被卸载，才可以设计相应的反馈处理流程。以下的列表是我在研究这一问题的思路：

　　1，注册BroadcastReceiver，监听"android.intent.action.PACKAGE_REMOVED"系统广播

　　结果：NO。未写代码，直接分析，卸载的第一步就是退出当前应用的主进程，而此广播是在已经卸载完成后才发出的，此时主进程都没有了，去哪onReceive()呢？

　　2，若能收到"将要卸载XX包"的系统广播，在主进程被退出之前就抢先进行反馈处理就好了，可惜没有这样的系统广播，不过经过调研，倒是发现了一个办法，读取系统log，当日志中包含"android.intent.action.DELETE"和自己的包名时，意味着自己将要被卸载。

　　结果：NO。调试时发现此方法有两个缺陷，（1）点击设置中的卸载按钮即发出此Intent，此时用户尚未在弹框中确认卸载；（2）pm命令卸载不出发此Intent，意味着被诸如手机安全管家，豌豆荚等软件卸载时，无法提前得知卸载意图。

　　3，由于时间点不容易把控，所以干脆不依赖系统广播或log，考虑到卸载过程会删除"/data/data/包名"目录，我们可以用线程直接轮询这个目录是否存在，以此为依据判断自己是否被卸载。

　　结果：NO。同方法1，主进程退出，相应的线程必定退出，线程还没等到判断目录是否存在就已经被销毁了。

　　4，改用C端进程轮询"/data/data/包名"目录是否存在

　　结果：YES。借助Java端进程fork出来的C端进程在应用被卸载后不会被销毁。

　　OK，上代码！

Activity启动时fork出C端进程轮询目录：

package main.activity;import pym.test.uninstalledmoniter.R;import android.app.Activity;import android.os.Bundle;import android.util.Log;/** * @author pengyiming * @note 监听此应用是否被卸载，若被卸载则弹出卸载反馈 * */public class UninstalledMoniterActivity extends Activity{    /* 数据段begin */    private static final String TAG = "UninstalledMoniterActivity";    /* 数据段end */        /* 函数段begin */    private native void init();    static    {        Log.d(TAG, "load libuninstalled_moniter");        System.loadLibrary("uninstalled_moniter");    }        @Override    public void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        Log.d(TAG, "onCreate");                setContentView(R.layout.uninstalled_moniter_layout);                init();    }    /* 函数段end */}

 

核心——native方法头文件：

 

/* 头文件begin */#include <jni.h>#include <stdio.h>#include <string.h>#include <android/log.h>#include <unistd.h>/* 头文件end *//* 宏定义begin *///清0宏#define MEM_ZERO(pDest, destSize) memset(pDest, 0, destSize)//LOG宏定义#define LOG_INFO(tag, msg) __android_log_write(ANDROID_LOG_INFO, tag, msg)#define LOG_DEBUG(tag, msg) __android_log_write(ANDROID_LOG_DEBUG, tag, msg)#define LOG_WARN(tag, msg) __android_log_write(ANDROID_LOG_WARN, tag, msg)#define LOG_ERROR(tag, msg) __android_log_write(ANDROID_LOG_ERROR, tag, msg)/* 宏定义end */#ifndef _Included_main_activity_UninstalledMoniterActivity#define _Included_main_activity_UninstalledMoniterActivity#ifdef __cplusplusextern "C" {#endif#undef main_activity_UninstalledMoniterActivity_MODE_PRIVATE#define main_activity_UninstalledMoniterActivity_MODE_PRIVATE 0L#undef main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE#define main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE 1L#undef main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE#define main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE 2L#undef main_activity_UninstalledMoniterActivity_MODE_APPEND#define main_activity_UninstalledMoniterActivity_MODE_APPEND 32768L#undef main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS#define main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS 4L#undef main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE#define main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE 1L#undef main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND#define main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND 2L#undef main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND#define main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND 4L#undef main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT#define main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT 8L#undef main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT#define main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT 16L#undef main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY#define main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY 32L#undef main_activity_UninstalledMoniterActivity_BIND_IMPORTANT#define main_activity_UninstalledMoniterActivity_BIND_IMPORTANT 64L#undef main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY#define main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY 128L#undef main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE#define main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE 1L#undef main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY#define main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY 2L#undef main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED#define main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED 4L#undef main_activity_UninstalledMoniterActivity_RESULT_CANCELED#define main_activity_UninstalledMoniterActivity_RESULT_CANCELED 0L#undef main_activity_UninstalledMoniterActivity_RESULT_OK#define main_activity_UninstalledMoniterActivity_RESULT_OK -1L#undef main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER#define main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER 1L#undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE#define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE 0L#undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER#define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER 1L#undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT#define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT 2L#undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL#define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L#undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL#define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L/* * Class:     main_activity_UninstalledMoniterActivity * Method:    init * Signature: ()V */JNIEXPORT void JNICALL Java_main_activity_UninstalledMoniterActivity_init(JNIEnv *, jobject);#ifdef __cplusplus}#endif#endif

 

核心——native方法实现：

 

/* 头文件begin */#include "main_activity_UninstalledMoniterActivity.h"/* 头文件end */#ifdef __cplusplusextern "C" {#endif/* 内全局变量begin */static char c_TAG[] = "UninstalledMoniterActivity.init";static jboolean b_IS_COPY = JNI_TRUE;/* 内全局变量 *//* * Class:     main_activity_UninstalledMoniterActivity * Method:    init * Signature: ()V */JNIEXPORT void JNICALL Java_main_activity_UninstalledMoniterActivity_init(JNIEnv *env, jobject obj){    jstring tag = (*env)->NewStringUTF(env, c_TAG);    //初始化log    LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)            , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "init OK"), &b_IS_COPY));    //fork子进程，以执行轮询任务    pid_t pid = fork();    if (pid < 0)    {        //出错log        LOG_ERROR((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)                , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "fork error !!!"), &b_IS_COPY));    }    else if (pid == 0)    {        //子进程轮询"/data/data/pym.test.uninstalledmoniter"目录是否存在，若不存在则说明已被卸载        while (1)        {            FILE *p_file = fopen("/data/data/pym.test.uninstalledmoniter", "r");            if (p_file != NULL)            {                fclose(p_file);                //目录存在log                LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)                            , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "I'm OK !!!"), &b_IS_COPY));                sleep(1);            }            else            {                //目录不存在log                LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY)                            , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "I'm NOT OK !!!"), &b_IS_COPY));                //执行命令am start -a android.intent.action.VIEW -d http://shouji.360.cn/web/uninstall/uninstall.html                execlp("am", "am", "start", "-a", "android.intent.action.VIEW", "-d", "http://shouji.360.cn/web/uninstall/uninstall.html", (char *)NULL);            }        }    }    else    {        //父进程直接退出，使子进程被init进程领养，以避免子进程僵死    }}#ifdef __cplusplus}#endif

 

注1：为了调试方便，包含<android/log.h>，使得so在执行过程中也可以像Java端一样方便得打出log。相应的mk文件需要加上以下两句声明

LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
LOCAL_LDLIBS += -L$(SYSROOT)/usr/lib -llog

注2：代码中引用了360手机卫士的反馈地址，仅供大家学习、测试使用~~~