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 pengyiming10 * @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 Activity15 {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 static23 {24 Log.d(TAG, "load libuninstalled_moniter");25 System.loadLibrary("uninstalled_moniter");26 }27 28 @Override29 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_UninstalledMoniterActivity21 #define _Included_main_activity_UninstalledMoniterActivity22 #ifdef __cplusplus23 extern "C" {24 #endif25 26 #undef main_activity_UninstalledMoniterActivity_MODE_PRIVATE27 #define main_activity_UninstalledMoniterActivity_MODE_PRIVATE 0L28 #undef main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE29 #define main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE 1L30 #undef main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE31 #define main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE 2L32 #undef main_activity_UninstalledMoniterActivity_MODE_APPEND33 #define main_activity_UninstalledMoniterActivity_MODE_APPEND 32768L34 #undef main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS35 #define main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS 4L36 #undef main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE37 #define main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE 1L38 #undef main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND39 #define main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND 2L40 #undef main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND41 #define main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND 4L42 #undef main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT43 #define main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT 8L44 #undef main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT45 #define main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT 16L46 #undef main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY47 #define main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY 32L48 #undef main_activity_UninstalledMoniterActivity_BIND_IMPORTANT49 #define main_activity_UninstalledMoniterActivity_BIND_IMPORTANT 64L50 #undef main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY51 #define main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY 128L52 #undef main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE53 #define main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE 1L54 #undef main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY55 #define main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY 2L56 #undef main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED57 #define main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED 4L58 #undef main_activity_UninstalledMoniterActivity_RESULT_CANCELED59 #define main_activity_UninstalledMoniterActivity_RESULT_CANCELED 0L60 #undef main_activity_UninstalledMoniterActivity_RESULT_OK61 #define main_activity_UninstalledMoniterActivity_RESULT_OK -1L62 #undef main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER63 #define main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER 1L64 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE65 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE 0L66 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER67 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER 1L68 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT69 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT 2L70 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL71 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L72 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL73 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L74 75 /*76 * Class: main_activity_UninstalledMoniterActivity77 * Method: init78 * Signature: ()V79 */80 JNIEXPORT void JNICALL Java_main_activity_UninstalledMoniterActivity_init(JNIEnv *, jobject);81 82 #ifdef __cplusplus83 }84 #endif85 #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_UninstalledMoniterActivity16 * Method: init17 * Signature: ()V18 */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log24 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log32 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log46 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 else52 {53 //目录不存在log54 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.html58 execlp("am", "am", "start", "-a", "android.intent.action.VIEW", "-d", "http://shouji.360.cn/web/uninstall/uninstall.html", (char *)NULL);59 }60 }61 }62 else63 {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 __cplusplus69 }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~~~
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