Java 无法从URL加载位图以在通知中显示-Android

我正在试着加载

在Android中转换为位图。我使用AsyncTask在后台执行下载，在onPostExecute中生成通知。将显示通知，但不显示图像

问题是返回的位图为空。网络调用中似乎没有错误，因为输入流和连接不为null

NotificationUtils中的方法：

public void showNotificationMessage(final String title, final String message, final String timeStamp, Intent intent, String imageUrl) {
        // Check for empty push message
        if (TextUtils.isEmpty(message))
            return;


        // notification icon
        final int icon = R.mipmap.ic_launcher;

        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
        final PendingIntent resultPendingIntent =
                PendingIntent.getActivity(
                        mContext,
                        0,
                        intent,
                        PendingIntent.FLAG_CANCEL_CURRENT
                );

        final NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
                mContext);

        final Uri alarmSound = Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE
                + "://" + mContext.getPackageName() + "/raw/notification");

        if (!TextUtils.isEmpty(imageUrl)) {

            if (imageUrl != null && imageUrl.length() > 4 && Patterns.WEB_URL.matcher(imageUrl).matches()) {
                /*ImageLoader imageLoader = ImageLoader.getInstance();
                imageLoader.loadImage(imageUrl, new SimpleImageLoadingListener() {
                    @Override
                    public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
                        // Do whatever you want with Bitmap
                        Log.i("ayusch",loadedImage.toString());
                    }
                });*/
                /*Bitmap test = null;
                try {
                    test = Picasso.with(mContext).load(imageUrl).get();
                } catch (IOException e) {
                    e.printStackTrace();
                }*/
                //Bitmap bitmap = getBitmapFromURL(imageUrl);
                /*ImageLoader imageLoader = ImageLoader.getInstance();
                imageLoader.loadImage(imageUrl, new SimpleImageLoadingListener() {
                    @Override
                    public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
                        // Do whatever you want with Bitmap
                        Log.i("ayusch",loadedImage.toString());
                    }
                });*/
                //Bitmap bitmap1 = imageLoader.loadImageSync(imageUrl);
                //Bitmap mbitmap = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.verifiedicon);
                new AsyncTask<String, String, Bitmap>() {
                    @Override
                    protected Bitmap doInBackground(String... params) {
                        try {
                            URL url = null;
                            try {
                                url = new URL(params[0]);
                            } catch (MalformedURLException e) {
                                e.printStackTrace();
                            }
                            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                            connection.setDoInput(true);
                            connection.connect();
                            InputStream input = connection.getInputStream();

                            Bitmap bmp = BitmapFactory.decodeStream(input);
                            input.close();
                            return bmp;
                        } catch (IOException e) {
                            e.printStackTrace();
                            return null;
                        }
                    }

                    @Override
                    protected void onPostExecute(Bitmap bitmap) {
                        super.onPostExecute(bitmap);

                        if (bitmap != null) {
                            showBigNotification(bitmap, mBuilder, icon, title, message, timeStamp, resultPendingIntent, alarmSound);
                        } else {
                            showSmallNotification(mBuilder, icon, title, message, timeStamp, resultPendingIntent, alarmSound);
                            Toast.makeText(mContext, "Bitmap is null", Toast.LENGTH_SHORT).show();
                        }
                    }
                }.execute(imageUrl);

            }
        } else {
            showSmallNotification(mBuilder, icon, title, message, timeStamp, resultPendingIntent, alarmSound);
            playNotificationSound();
        }
    }

我已经尝试过UniversalImageLoader，如下所示：

ImageLoader imageLoader = ImageLoader.getInstance();
                imageLoader.loadImage(imageUrl, new SimpleImageLoadingListener() {
                    @Override
                    public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
                        // Do whatever you want with Bitmap
                        Log.i("ayusch",loadedImage.toString());
                    }
                });

当我使用它时，通知根本不会显示

我试着用毕加索来做：

Bitmap test = Picasso.with(mContext).load(imageUrl).get();

但同样，通知未显示

---

请帮助

此问题已解决我已尝试此操作，但未成功…..（您正在尝试哪个版本的Android？minsdkversion是15此问题已解决我已尝试此操作，但未成功…..（您正在尝试哪个版本的Android？minsdkversion是15）

Bitmap test = Picasso.with(mContext).load(imageUrl).get();