解析JSON数据，加载到ListView一片空白

Question

这是主Activity：public class ListViewDownLoad extends Activity{ private ListView mListView; private static String URL="www.imooc.com/api/teacher?type=4&num=30"; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.list_view); mListView=(ListView) findViewById(R.id.lv_main); new NewsAsyncTask().execute(URL); } private String readStream(InputStream is){ InputStreamReader isr; String result=""; try { String line=""; isr = new InputStreamReader(is,"utf-8"); BufferedReader br=new BufferedReader(isr); while((line = br.readLine())!=null){ result+=line; } }catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return result; } class NewsAsyncTask extends AsyncTask<String,Void,List<NewsBean>>{ @Override protected List<NewsBean> doInBackground(String... arg0) { List<NewsBean> newsBeanList = new ArrayList<NewsBean>(); try { String jsonString = readStream(new URL(arg0[0]).openStream()); JSONObject jsonObject; NewsBean newsBean; jsonObject = new JSONObject(jsonString); JSONArray jsonArray = jsonObject.getJSONArray("data"); for (int i = 0; i < jsonArray.length(); i++) { jsonObject = jsonArray.getJSONObject(i); newsBean = new NewsBean(); newsBean.newsIconUrl=jsonObject.getString("picSmall"); newsBean.newsTitle=jsonObject.getString("name"); newsBean.newsContent=jsonObject.getString("description"); newsBeanList.add(newsBean); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println(newsBeanList); return newsBeanList; } @Override protected void onPostExecute(List<NewsBean> result) { // TODO Auto-generated method stub super.onPostExecute(result); NewsAdapter adapter = new NewsAdapter(ListViewDownLoad.this, result); mListView.setAdapter(adapter); } }}这是适配器：public class NewsAdapter extends BaseAdapter{ private List<NewsBean> mList; private LayoutInflater mInflater; public NewsAdapter(Context context,List<NewsBean> data){ mList = data; mInflater = LayoutInflater.from(context); } @Override public int getCount() { // TODO Auto-generated method stub return mList.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return mList.get(position); } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) {        ViewHolder viewHolder = null;        if (convertView==null) { viewHolder = new ViewHolder(); convertView = mInflater.inflate(R.layout.item_layout, null); viewHolder.ivIcon = (ImageView) convertView.findViewById(R.id.iv_icon); viewHolder.tvTitle = (TextView) convertView.findViewById(R.id.tv_title); viewHolder.tvContent = (TextView) convertView.findViewById(R.id.tv_content); convertView.setTag(viewHolder); }else{ viewHolder = (ViewHolder) convertView.getTag(); }        viewHolder.ivIcon.setImageResource(R.drawable.ic_launcher);        viewHolder.tvTitle.setText(mList.get(position).newsTitle);        viewHolder.tvContent.setText(mList.get(position).newsContent); return convertView; } class ViewHolder{ public TextView tvTitle; public TextView tvContent; public ImageView ivIcon; } }

Answer 1

还没解决吗我运行也是白板

Answer 2

访问不了

Answer 3

我也遇到这个问题了，请问题主解决了嘛。？能说一下是怎么解决的嘛？

Answer 4

mList = data;

这个data有值吗？