如何知道我的應用程序是在前台還是后台，android？

Question

我需要檢查我的應用程序是在后台還是前台運行，然后執行一些相對於它的操作。

我搜索了很多，但沒有明確的解決方案。

1. 在其 onPause() 和 onResume() 方法中創建一個父活動，保留一些變量以相應地更新它們。 當您創建任何新活動時，繼承您的父活動。 雖然這是我覺得完成我的任務的最佳解決方案，但有時如果即使應用程序在后台單擊電源按鈕，也會調用 onResume()。

2. 使用 GETTASKS 權限 - 這個解決方案也很好。 但它只能用於調試目的。 如果您想將您的應用程序放在 Google Play 商店中，則不會。

獲得運行任務

任何其他首選解決方案？

Answer 1

嗯，這解決了我的問題：

  private boolean isAppOnForeground(Context context,String appPackageName) {
    ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    List<ActivityManager.RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();
    if (appProcesses == null) {
        return false;
    }
    final String packageName = appPackageName;
    for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {
        if (appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND && appProcess.processName.equals(packageName)) {
 //                Log.e("app",appPackageName);
            return true;
        }
    }
    return false;
}

Answer 2

原始答案： https : //stackoverflow.com/a/60212452/10004454根據 Android 文檔推薦的做法是

class MyApplication : Application(), LifecycleObserver {

override fun onCreate() {
    super.onCreate()
    ProcessLifecycleOwner.get().lifecycle.addObserver(this);
}

fun isActivityVisible(): String {
    return ProcessLifecycleOwner.get().lifecycle.currentState.name
}

@OnLifecycleEvent(Lifecycle.Event.ON_STOP)
fun onAppBackgrounded() {
    //App in background

    Log.e(TAG, "************* backgrounded")
    Log.e(TAG, "************* ${isActivityVisible()}")
}

@OnLifecycleEvent(Lifecycle.Event.ON_START)
fun onAppForegrounded() {

    Log.e(TAG, "************* foregrounded")
    Log.e(TAG, "************* ${isActivityVisible()}")
    // App in foreground
}}

在您的 gradle（應用程序）中添加： implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"

然后在運行時檢查狀態調用MyApplication().isActivityVisible()

Answer 3

使用AppVisibilityDetector ，我實現了這個類來檢測應用程序的可見性狀態。 它可以檢測前台和后台狀態並執行回調方法。

 AppVisibilityDetector.init(MyApp.this, new AppVisibilityCallback() {
    @Override
    public void onAppGotoForeground() {
        //app is from background to foreground
    }
    @Override
    public void onAppGotoBackground() {
        //app is from foreground to background
    }
});

MyApp 是您的應用程序類

public class MyApp extends Application { ... }

您不需要在您的活動中添加一些其他代碼或在 AndroidManifest.xml 中添加任何權限

Answer 4

您可以使用此代碼獲取應用程序的前台（ true ）運行狀態

public boolean isAppForground(Context mContext) {
    ActivityManager am = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
    List<RunningTaskInfo> tasks = am.getRunningTasks(1);
    if (!tasks.isEmpty()) {
        ComponentName topActivity = tasks.get(0).topActivity;
        if (!topActivity.getPackageName().equals(mContext.getPackageName())) {
            return false;
        }
    }
    return true;
}

Answer 5

使用以下函數檢查您的應用程序是在后台還是前台

    public static Boolean getProcessState(Context mContext) {
    ActivityManager am = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);

    boolean noProcessOnForeground = true;
    boolean isProcessForeground = false;

    System.out.println("Checking if process: " + mContext.getApplicationInfo().processName + " is Foreground or Background");
    List<ActivityManager.RunningAppProcessInfo> current_processes = am.getRunningAppProcesses();
    for (ActivityManager.RunningAppProcessInfo appProcess : current_processes) {
        if (appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {

            noProcessOnForeground = false;
            if ((mContext.getApplicationInfo().processName).equalsIgnoreCase(appProcess.processName)) {

                isProcessForeground = true;
                System.out.println("Process is Foreground");
                break;
                //   Toast.makeText(getApplicationContext(), "Process is Foreground", Toast.LENGTH_SHORT).show();
            } else {


                System.out.println("Process is Background");
                //    Toast.makeText(getApplicationContext(), "Process is Background", Toast.LENGTH_SHORT).show();
                isProcessForeground = false;
                break;
            }
        }
    }

    if (noProcessOnForeground) {

        System.out.println("there is no process on foreground so setting " + mContext.getApplicationInfo().processName + " as background");
        isProcessForeground = false;
    }

    return isProcessForeground;
}

Answer 6

只想在活動/片段中使用以下代碼：

final boolean isAlive = AppVisibilityHelper.isForeground(HomeActivity.this);

想要制作一個如下所示的課程：

 public class AppVisibilityHelper{

        public static boolean isForeground(final Context context) {
            final String packageName = "com.acb.android";
            ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
            List<ActivityManager.RunningTaskInfo> runningTaskInfo = manager.getRunningTasks(1);
            ComponentName componentInfo = runningTaskInfo.get(0).topActivity;
            return componentInfo.getPackageName().equals(packageName);
        }
    }

如果您想在每一秒后檢查一次，請在 Activity 中使用以下代碼：

 Runnable CheckAppIsRunning = new Runnable() {
        @Override
        public void run() {
           final boolean isAlive = AppVisibilityHelper.isForeground(HomeActivity.this);
                if (isAlive) {
                    // App is running
                } else {
                    // App is not running
                }
            }
            appIsRuningHandler.postDelayed(CheckAppIsRunning, 1000);
        }
    };

在 onCreate() 中只需調用一次，例如：

appIsRuningHandler.postDelayed(CheckAppIsRunning, 1000);

Answer 7

檢查應用程序處於前台狀態還是后台狀態

ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
   List<ActivityManager.RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();

   final String packageName = getPackageName();
    for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses)
   {

   if (appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_BACKGROUND && appProcess.processName.equals(packageName))
      {

       //if app in background state this will execute

        Intent intent = getPackageManager().getLaunchIntentForPackage("hinditextonphoto.com.allcomponents");
        startActivity(intent);
        System.out.println("bbbbbbbbbbbbb    background");
      }

       else if (appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND && appProcess.processName.equals(packageName))
       {

       //if app in forground state this will execute
         System.out.println("bbbbbbbbbbbbb    forground");

       }

  }

Answer 8

您可以使用ActivityManager.RunningAppProcessInfo類來檢查應用程序狀態。

public boolean isForegrounded() {
    ActivityManager.RunningAppProcessInfo appProcessInfo = new ActivityManager.RunningAppProcessInfo();
    ActivityManager.getMyMemoryState(appProcessInfo);
    return (appProcessInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND ||
            appProcessInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_VISIBLE);
}

Answer 9

您可以使用流程生命周期所有者檢查這一點。

fun isAppOnForeground(): Boolean {
return ProcessLifecycleOwner.get().getLifecycle().getCurrentState()
    .isAtLeast(Lifecycle.State.STARTED);
}