Question

我正在开发Android应用程序，我正在尝试将InputStream解码为Bitmap。

Bitmap bmp = BitmapFactory.decodeStream(s);

QBContent.downloadFileTask（...）中的上一行抛出NetworkOnMainThread异常。

以下是参考代码：

ChatAdapter的getView（）

      @Override
public View getView(int position, View convertView, ViewGroup parent) {
    final ViewHolder holder;
    QBChatMessage chatMessage = getItem(position);
    LayoutInflater vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    int type = getItemViewType(position);
    if (convertView == null) {
        convertView = vi.inflate(R.layout.list_item_image, parent, false);
        holder = createViewHolder(convertView);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }

    QBUser currentUser = ChatService.getInstance().getCurrentUser();
    boolean isOutgoing = chatMessage.getSenderId() == null || chatMessage.getSenderId().equals(currentUser.getId());
    setAlignment(holder, isOutgoing);

    Collection<QBAttachment> attachments = chatMessage.getAttachments();
    //attachments.
    if (attachments != null && attachments.size() > 0) {

        String imageid = "";
        for (QBAttachment attachment : attachments) {
            imageid = attachment.getId();
        }

        final int imageid1 = Integer.parseInt(imageid);

        QBContent.downloadFileTask(imageid1, new QBEntityCallbackImpl<InputStream>() {
            @Override
            public void onSuccess(InputStream inputS, Bundle params) {

                if (inputS != null) {
                    Bitmap bmp = BitmapFactory.decodeStream(inputS);
                    Drawable d = new BitmapDrawable(context.getResources(), bmp);
                    if (holder.image_attachment != null)
                        holder.image_attachment.setImageDrawable(d);
                }
            }
            @Override
            public void onError(List<String> errors) {
                Log.d("Image Download Error : ", errors.toString());
            }
        }, new QBProgressCallback() {
            @Override
            public void onProgressUpdate(int progress) {
            }
        });
    } 
    return convertView;
}

我在这做错了什么？请帮帮我。

Answer 1

试试这个

private class SampleAsync extends AsyncTask<Void, Void, Bitmap> {

    @Override
    protected Bitmap doInBackground(Void... params) {
        // your background code fetch InputStream
        InputStream s = //your inputstream ;
        Bitmap bmp = BitmapFactory.decodeStream(s);
        return bmp;
    }

    @Override
    protected void onPostExecute(Bitmap bmp) {
        super.onPostExecute(bmp);
        if(bmp != null){
            Drawable d = new BitmapDrawable(context.getResources(), bmp);
            if(holder.image_attachment != null)
                holder.image_attachment.setImageDrawable(d);
        }
    }
}

Answer 2

在doInbackground方法中执行相同操作并在UI线程内执行操作

Answer 3

你是间接地在主线程上调用网络，因为适配器用于更新ui并且它们在主线程上运行。要解决此问题，请将带有适配器的完整代码移动到另一个asyncTask，或者从适配器中删除asynctask调用。

Answer 4

最后我得到了答案。

1。删除了AsyncTask并直接调用了QBContent.downloadFileTask（...）。

2。修改了QBContent.downloadFileTask（...）。这里我在后台线程中将InputStream解码为BitMap，以前我是在UI线程中进行的。

QBContent.downloadFileTask(imageid1, new QBEntityCallbackImpl<InputStream>() {
            @Override
            public void onSuccess(final InputStream inputS, Bundle params) {

                if (inputS != null) {
                    new Thread() {
                        public void run() {
                            final Bitmap bmp = BitmapFactory.decodeStream(inputS);
                            try {
                                context.runOnUiThread(new Runnable() {
                                    @Override
                                    public void run() {
                                        Drawable d = new BitmapDrawable(context.getResources(), bmp);
                                        if (holder.image_attachment != null)
                                            holder.image_attachment.setImageDrawable(d);
                                    }
                                });
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                        }
                    }.start();
                }

            }

            @Override
            public void onError(List<String> errors) {
                Log.d("Image Download Error : ", errors.toString());

            }
        }, new QBProgressCallback() {
            @Override
            public void onProgressUpdate(int progress) {

            }
        });

BitmapFactory.decodeStream抛出NetworkOnMainThreadException - Android

4 个答案: