版权声明：本文为博主原创文章，未经博主允许不得转载。//当前应用是否处于前台private boolean isForeground(Context context) {if (context != null) {ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);List<ActivityManager.RunningAppProcessInfo> processes = activityManager.getRunningAppProcesses();for (ActivityManager.RunningAppProcessInfo processInfo: processes) {if (processInfo.processName.equals(context.getPackageName())) {if (processInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {return true;}}}}return false;}可以根据importance的不同来判断前台或后台
RunningAppProcessInfo 里面的常量IMOPORTANCE就是上面所说的前台后台，其实IMOPORTANCE是表示这个app进程的重要性，因为系统回收时候，会根据IMOPORTANCE来回收进程的。具体可以去看文档。。public static final int IMPORTANCE_BACKGROUND = 400//后台public static final int IMPORTANCE_EMPTY = 500//空进程public static final int IMPORTANCE_FOREGROUND = 100//在屏幕最前端、可获取到焦点 可理解为Activity生命周期的OnResume();public static final int IMPORTANCE_SERVICE = 300//在服务中public static final int IMPORTANCE_VISIBLE = 200//在屏幕前端、获取不到焦点可理解为Activity生命周期的OnStart();

但上面的方法有的机型不支持，下面这个方法还是比较靠谱的，但需要一个权限
< uses-permission Android:name =“android.permission.GET_TASKS” />//当前应用是否处于前台private boolean isForeground(Context context) {if (context != null) {ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);ComponentName cn = am.getRunningTasks(1).get(0).topActivity;String currentPackageName = cn.getPackageName();if (!TextUtils.isEmpty(currentPackageName) && currentPackageName.equals(context.getPackageName())) {return true;}return false;}return false;}版本4.0以上，可以使用ActivityLifecycleif (Build.VERSION.SDK_INT >= 14) {lifecycle = new SimpleActivityLifecycle();registerActivityLifecycleCallbacks(lifecycle);public class SimpleActivityLifecycle implements Application.ActivityLifecycleCallbacks {private boolean isForeground = false;//应用是否处于前端
@Overridepublic void onActivityCreated(Activity activity, Bundle savedInstanceState) {}@Overridepublic void onActivityStarted(Activity activity) {}@Overridepublic void onActivityResumed(Activity activity) {isForeground = true;}@Overridepublic void onActivityPaused(Activity activity) {isForeground = false;}@Overridepublic void onActivityStopped(Activity activity) {}@Overridepublic void onActivitySaveInstanceState(Activity activity, Bundle outState) {}@Overridepublic void onActivityDestroyed(Activity activity) {}public boolean isForeground() {return isForeground;}
}