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。