我们可以在应用程序之外创建一个弹出窗口吗？(Android Studio)

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

public class MyPopupService extends Service {
    private WindowManager mWindowManager;
    private View mPopupView;

    @Override
    public void onCreate() {
        super.onCreate();
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        mPopupView = LayoutInflater.from(this).inflate(R.layout.popup_layout, null);
        // 设置弹出窗口的布局和属性
        WindowManager.LayoutParams params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
                PixelFormat.TRANSLUCENT);
        // 设置弹出窗口的位置
        params.gravity = Gravity.TOP | Gravity.START;
        params.x = 100;
        params.y = 100;
        // 添加弹出窗口到窗口管理器
        mWindowManager.addView(mPopupView, params);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        // 移除弹出窗口
        if (mPopupView != null) {
            mWindowManager.removeView(mPopupView);
        }
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

Intent intent = new Intent(this, MyPopupService.class);
startService(intent);