Android 前后台进程切换判断

来源：互联网发布：淘宝签署开店无法同意编辑：程序博客网时间：2024/06/05 05:29

项目有个需求是，应用退到后台 5 分钟以后再回到前台弹出手势密码锁界面提示用户解锁，目前已经完成分享一下实现的方法

public class GestureLockManager {    private DownTimer downTimer;    private boolean isFromBack;    private boolean isPop;    private static GestureLockManager sS;    private GestureLockManager() {    }    static {        sS = new GestureLockManager();    }    public static GestureLockManager getInstance() {        if (sS == null) {            sS = new GestureLockManager();        }        return sS;    }    public void init() {        //need Android API > 14        RceApp.getInstance().registerActivityLifecycleCallbacks(new Application.ActivityLifecycleCallbacks() {            @Override            public void onActivityCreated(Activity activity, Bundle savedInstanceState) {//进程启动                if (activity.getClass().equals(MainActivity.class)) {                    isFromBack = false;                    long cacheTime = CacheTask.getInstance().getGestureTime();                    long currentTime = System.currentTimeMillis();                    if (cacheTime != 0 && (currentTime - cacheTime) / 60000 > 5 && activity.getIntent() != null && activity.getIntent().getData() != null && "true".equals(activity.getIntent().getData().getQueryParameter("isFromPush"))) {                        activity.startActivity(new Intent(activity, GestureLoginActivity.class));                        //如果不是第一次安装而且杀进程时间间隔大于 5 分钟 并且 是来的 push 消息                    }                }            }            @Override            public void onActivityStarted(Activity activity) {//进程在前台                if (!io.rong.common.SystemUtils.isInBackground(activity) && isFromBack && LoginActivity.class != activity.getClass()) {                    downTimer.stopDown();                    if (isPop && CacheTask.getInstance().getGestureLock() != null) {                        activity.startActivity(new Intent(activity, GestureLoginActivity.class));                    }                    isPop = false;                    isFromBack = false;                }            }            @Override            public void onActivityResumed(Activity activity) {            }            @Override            public void onActivityPaused(Activity activity) {            }            @Override            public void onActivityStopped(Activity activity) {//进程切入后台                if (io.rong.common.SystemUtils.isInBackground(activity)) {                    isFromBack = true;                    downTimer.startDown(1000 * 60 * 5);                }            }            @Override            public void onActivitySaveInstanceState(Activity activity, Bundle outState) {            }            @Override            public void onActivityDestroyed(Activity activity) {//进程被杀死                if (activity.getClass().equals(MainActivity.class)) {                    CacheTask.getInstance().cacheGestureTime(currentTimeMillis()); //TODO 可能存在杀死进程没有 cache 当前时间戳的情况                }            }        });        downTimer = new DownTimer();        downTimer.setListener(new DownTimer.DownTimerListener() {            @Override            public void onFinish() {                isPop = true;            }        });    }}

上面是主要实现代码，建议在 application 类做初始化

 GestureLockManager.getInstance().init();

其中工具类判断的关键代码

    public static boolean isInBackground(Context context) {        boolean isInBackground = true;        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT_WATCH) {            List<ActivityManager.RunningAppProcessInfo> runningProcesses = am.getRunningAppProcesses();            if (runningProcesses == null) {                return false;            }            for (ActivityManager.RunningAppProcessInfo processInfo : runningProcesses) {                //前台程序                if (processInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {                    for (String activeProcess : processInfo.pkgList) {                        if (activeProcess.equals(context.getPackageName())) {                            return false;                        }                    }                }            }        } else {            List<ActivityManager.RunningTaskInfo> taskInfo = am.getRunningTasks(1);            ComponentName componentInfo = taskInfo.get(0).topActivity;            if (componentInfo.getPackageName().equals(context.getPackageName())) {                isInBackground = false;            }        }        return isInBackground;    }

最后需要记得这个 API 是需要大于 14 才可以使用，对 4.0 以下的手机应该是无效的。

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