如何在android的非活动类中打开一个小窗口

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

public class FloatingWindowService extends Service {
    private WindowManager mWindowManager;
    private View mFloatingView;

    @Override
    public void onCreate() {
        super.onCreate();
        // 初始化WindowManager
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);

        // 创建并设置小窗口的布局
        mFloatingView = LayoutInflater.from(this).inflate(R.layout.floating_window_layout, null);

        // 设置小窗口的参数
        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);

        // 添加小窗口到WindowManager
        mWindowManager.addView(mFloatingView, params);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        // 移除小窗口
        if (mFloatingView != null) {
            mWindowManager.removeView(mFloatingView);
        }
    }

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

Intent intent = new Intent(context, FloatingWindowService.class);
context.startService(intent);