php - 如何在异步任务上加载图像

Question

Android (Java) 使用 asynctask 加载图像

        @Override
        protected String doInBackground(String... arg0) {
            mNewsList = new ArrayList<HashMap<String, String>>();
            JSONParser jParser = new JSONParser();
            JSONObject json = jParser.getJSONFromUrl(URL);
            try {
                mNews = json.getJSONArray(TAG_POSTS);
                for (int i = 0; i < mNews.length(); i++) {
                    JSONObject c = mNews.getJSONObject(i);
                    String image = c.getString(TAG_IMAGE);

            HashMap<String, String> map = new HashMap<String, String>();

                    map.put(TAG_IMAGE, image);
                    mNewsList.add(map);
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
            return null;
        }

        protected void onPostExecute(String file_url) {
        ListAdapter adapter = new SimpleAdapter(Home.this, mNewsList,
                    R.layout.news_list, new String[] {TAG_IMAGE},
                    new int[]{R.id.ivImage});
            newsList.setAdapter(adapter);
        }

如何使用asynctask加载图像

尝试使用惰性列表适配器，但不适合我的需求。

Answer 1

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
        ImageView bmImage;

        public DownloadImageTask(ImageView bmImage) {
            this.bmImage = bmImage;
        }

        protected Bitmap doInBackground(String... urls) {
            String urldisplay = urls[0];
            Bitmap mIcon11 = null;
            try {
                InputStream in = new java.net.URL(urldisplay).openStream();
                mIcon11 = BitmapFactory.decodeStream(in);
            } catch (Exception e) {
                Log.e("Error", e.getMessage());
                e.printStackTrace();
            }
            return mIcon11;
        }

        protected void onPostExecute(Bitmap result) {
            bmImage.setImageBitmap(result);
        }

    }