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:
1 package main.activity; 2 3 import pym.test.uninstalledmoniter.R; 4 import android.app.Activity; 5 import android.os.Bundle; 6 import android.util.Log; 7 8 /** 9 * @author pengyiming 10 * @note 监听此应用是否被卸载,若被卸载则弹出卸载反馈 11 * 12 */ 13 14 public class UninstalledMoniterActivity extends Activity 15 { 16 /* 数据段begin */ 17 private static final String TAG = "UninstalledMoniterActivity"; 18 /* 数据段end */ 19 20 /* 函数段begin */ 21 private native void init(); 22 static 23 { 24 Log.d(TAG, "load libuninstalled_moniter"); 25 System.loadLibrary("uninstalled_moniter"); 26 } 27 28 @Override 29 public void onCreate(Bundle savedInstanceState) 30 { 31 super.onCreate(savedInstanceState); 32 Log.d(TAG, "onCreate"); 33 34 setContentView(R.layout.uninstalled_moniter_layout); 35 36 init(); 37 } 38 /* 函数段end */ 39 }
核心——native方法头文件:
1 /* 头文件begin */ 2 #include <jni.h> 3 #include <stdio.h> 4 #include <string.h> 5 #include <android/log.h> 6 #include <unistd.h> 7 /* 头文件end */ 8 9 /* 宏定义begin */ 10 //清0宏 11 #define MEM_ZERO(pDest, destSize) memset(pDest, 0, destSize) 12 13 //LOG宏定义 14 #define LOG_INFO(tag, msg) __android_log_write(ANDROID_LOG_INFO, tag, msg) 15 #define LOG_DEBUG(tag, msg) __android_log_write(ANDROID_LOG_DEBUG, tag, msg) 16 #define LOG_WARN(tag, msg) __android_log_write(ANDROID_LOG_WARN, tag, msg) 17 #define LOG_ERROR(tag, msg) __android_log_write(ANDROID_LOG_ERROR, tag, msg) 18 /* 宏定义end */ 19 20 #ifndef _Included_main_activity_UninstalledMoniterActivity 21 #define _Included_main_activity_UninstalledMoniterActivity 22 #ifdef __cplusplus 23 extern "C" { 24 #endif 25 26 #undef main_activity_UninstalledMoniterActivity_MODE_PRIVATE 27 #define main_activity_UninstalledMoniterActivity_MODE_PRIVATE 0L 28 #undef main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE 29 #define main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE 1L 30 #undef main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE 31 #define main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE 2L 32 #undef main_activity_UninstalledMoniterActivity_MODE_APPEND 33 #define main_activity_UninstalledMoniterActivity_MODE_APPEND 32768L 34 #undef main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS 35 #define main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS 4L 36 #undef main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE 37 #define main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE 1L 38 #undef main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND 39 #define main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND 2L 40 #undef main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND 41 #define main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND 4L 42 #undef main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT 43 #define main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT 8L 44 #undef main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT 45 #define main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT 16L 46 #undef main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY 47 #define main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY 32L 48 #undef main_activity_UninstalledMoniterActivity_BIND_IMPORTANT 49 #define main_activity_UninstalledMoniterActivity_BIND_IMPORTANT 64L 50 #undef main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY 51 #define main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY 128L 52 #undef main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE 53 #define main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE 1L 54 #undef main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY 55 #define main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY 2L 56 #undef main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED 57 #define main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED 4L 58 #undef main_activity_UninstalledMoniterActivity_RESULT_CANCELED 59 #define main_activity_UninstalledMoniterActivity_RESULT_CANCELED 0L 60 #undef main_activity_UninstalledMoniterActivity_RESULT_OK 61 #define main_activity_UninstalledMoniterActivity_RESULT_OK -1L 62 #undef main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER 63 #define main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER 1L 64 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE 65 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE 0L 66 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER 67 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER 1L 68 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT 69 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT 2L 70 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL 71 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L 72 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL 73 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L 74 75 /* 76 * Class: main_activity_UninstalledMoniterActivity 77 * Method: init 78 * Signature: ()V 79 */ 80 JNIEXPORT void JNICALL Java_main_activity_UninstalledMoniterActivity_init(JNIEnv *, jobject); 81 82 #ifdef __cplusplus 83 } 84 #endif 85 #endif
核心——native方法实现:
1 /* 头文件begin */ 2 #include "main_activity_UninstalledMoniterActivity.h" 3 /* 头文件end */ 4 5 #ifdef __cplusplus 6 extern "C" { 7 #endif 8 9 /* 内全局变量begin */ 10 static char c_TAG[] = "UninstalledMoniterActivity.init"; 11 static jboolean b_IS_COPY = JNI_TRUE; 12 /* 内全局变量 */ 13 14 /* 15 * Class: main_activity_UninstalledMoniterActivity 16 * Method: init 17 * Signature: ()V 18 */ 19 JNIEXPORT void JNICALL Java_main_activity_UninstalledMoniterActivity_init(JNIEnv *env, jobject obj) 20 { 21 jstring tag = (*env)->NewStringUTF(env, c_TAG); 22 23 //初始化log 24 LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY) 25 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "init OK"), &b_IS_COPY)); 26 27 //fork子进程,以执行轮询任务 28 pid_t pid = fork(); 29 if (pid < 0) 30 { 31 //出错log 32 LOG_ERROR((*env)->GetStringUTFChars(env, tag, &b_IS_COPY) 33 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "fork error !!!"), &b_IS_COPY)); 34 } 35 else if (pid == 0) 36 { 37 //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 38 while (1) 39 { 40 FILE *p_file = fopen("/data/data/pym.test.uninstalledmoniter", "r"); 41 if (p_file != NULL) 42 { 43 fclose(p_file); 44 45 //目录存在log 46 LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY) 47 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "I'm OK !!!"), &b_IS_COPY)); 48 49 sleep(1); 50 } 51 else 52 { 53 //目录不存在log 54 LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY) 55 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "I'm NOT OK !!!"), &b_IS_COPY)); 56 57 //执行命令am start -a android.intent.action.VIEW -d http://shouji.360.cn/web/uninstall/uninstall.html 58 execlp("am", "am", "start", "-a", "android.intent.action.VIEW", "-d", "http://shouji.360.cn/web/uninstall/uninstall.html", (char *)NULL); 59 } 60 } 61 } 62 else 63 { 64 //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 65 } 66 } 67 68 #ifdef __cplusplus 69 } 70 #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~~~