android:如何检查应用程序是否在后台运行

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

String packageName = "com.example.myapp"; // 替换为你的应用程序包名
for (ActivityManager.RunningAppProcessInfo processInfo : runningProcesses) {
    if (processInfo.processName.equals(packageName)) {
        // 应用程序在前台运行
        break;
    }
}

public class MyApplication extends Application implements Application.ActivityLifecycleCallbacks {

    private int activityCount = 0;

    @Override
    public void onCreate() {
        super.onCreate();
        registerActivityLifecycleCallbacks(this);
    }

    @Override
    public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
        activityCount++;
    }

    @Override
    public void onActivityStarted(Activity activity) {
        // 应用程序进入前台
    }

    @Override
    public void onActivityResumed(Activity activity) {
        // 应用程序进入前台
    }

    @Override
    public void onActivityPaused(Activity activity) {
        // 应用程序进入后台
    }

    @Override
    public void onActivityStopped(Activity activity) {
        // 应用程序进入后台
    }

    @Override
    public void onActivityDestroyed(Activity activity) {
        activityCount--;
        if (activityCount == 0) {
            // 应用程序进入后台
        }
    }

    @Override
    public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
    }

    @Override
    public void onActivityResumed(Activity activity) {
    }
}