通知栏不为空时如何显示通知图像？

Question

我已经将此代码用于在android的通知栏中显示和图像，它可以找到并正确显示图像

问题是这样的，当我从其他应用收到其他通知时，它不显示图像，而仅显示标题和文本而没有图像。

如何强制它在任何情况下显示图像？

这是我的代码：

public class generatePictureStyleNotification extends AsyncTask<String, Void, Bitmap> {

    private Context mContext;
    private String title, message, imageUrl;

    public generatePictureStyleNotification(Context context, String title, String message, String imageUrl) {
        super();
        this.mContext = context;
        this.title = title;
        this.message = message;
        this.imageUrl = imageUrl;
    }

    @Override
    protected Bitmap doInBackground(String... params) {

        InputStream in;
        try {
            URL url = new URL(this.imageUrl);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.connect();
            in = connection.getInputStream();
            Bitmap myBitmap = BitmapFactory.decodeStream(in);
            return myBitmap;
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    @Override
    protected void onPostExecute(Bitmap result) {
        super.onPostExecute(result);


        Intent resultIntent = resultIntent = new Intent(mContext, FistActiivty.class);
        resultIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        resultIntent.putExtra("onvan", title);
        resultIntent.putExtra("message", message);
        resultIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP
                | Intent.FLAG_ACTIVITY_SINGLE_TOP);

        TaskStackBuilder TSB = TaskStackBuilder.create(mContext);
        TSB.addParentStack( FistActiivty.class);
        TSB.addNextIntent(resultIntent);
        PendingIntent resultPendingIntent =
                TSB.getPendingIntent(
                        0,
                        PendingIntent.FLAG_UPDATE_CURRENT
                );

        mBuilder = new NotificationCompat.Builder(mContext, NOTIFICATION_CHANNEL_ID);
        mBuilder.setSmallIcon(R.mipmap.ic_launcher);
        mBuilder.setContentIntent(resultPendingIntent);
        mBuilder.setContentTitle(title)
                .setContentText(message)
                .setAutoCancel(true)
                .setSound(Settings.System.DEFAULT_NOTIFICATION_URI)
                .setContentIntent(resultPendingIntent)
                .setStyle(new NotificationCompat.BigPictureStyle().bigPicture(result))
        ;

       mNotificationManager = (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);

    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
        int importance = NotificationManager.IMPORTANCE_HIGH;
        NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "NOTIFICATION_CHANNEL_NAME", importance);
        notificationChannel.enableLights(true);
        notificationChannel.setLightColor(Color.RED);
        notificationChannel.enableVibration(true);
        notificationChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});
        assert mNotificationManager != null;
        mBuilder.setChannelId(NOTIFICATION_CHANNEL_ID);
        mNotificationManager.createNotificationChannel(notificationChannel);
    }
    assert mNotificationManager != null;
    mNotificationManager.notify(0 /* Request Code */, mBuilder.build());
    }
}