Android：Fragment加载速度太慢

我正在创建一个与Web服务器一起工作的应用程序,因此有很多查询要做.在我的片段中,名为“tab_profile”,我调用2个API查询,还有许多其他人在我的自定义ListView上加载图像.

所以我的问题是这个片段在加载(井连接)时需要1-2秒,甚至在连接不良时崩溃,例如3G.

代码看起来像这样(当然是短版)：

public class tab_profile extends Fragment implements AdapterView.onItemClickListener {
private String imagepath = null;
private ImageView imageview = null;
View rootView = null;
private ArrayList<PollItem> arrayPolls;

@Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceStatE) {
    rootView = inflater.inflate(R.layout.tab_profile,container,falsE);

    final Button button_follower    = (Button) rootView.findViewById(R.id.button_follower);
    final Button button_following   = (Button) rootView.findViewById(R.id.button_following);
    final TextView text_username    = (TextView) rootView.findViewById(R.id.text_userName);
    imageview                       = (ImageView) rootView.findViewById(R.id.img_own_pp);
    final Session session           = new Session(getActivity());
    final Network network           = new Network(getActivity());

    text_username.setText(session.getValue("username"));
    if(session.getValue("username").length() < 3) {
        getActivity().finish();
        return null;
    }

    JSONArray arr;
    String res = network.POST("{\"token\":\"" + session.getValue("token") + "\"}","profile.PHP");
    try {
        JSONObject obj = new JSONObject(res);
        arr = obj.getJSONArray("data");

        if (!obj.get("status").equals("false")) {

            button_follower.setText("Follower\n" + arr.getJSONObject(0).getString("follower"));
            button_following.setText("Following\n" + arr.getJSONObject(0).getString("following"));

            if (arr.getJSONObject(0).getString("pp").equals("true")) {
                network.setImageViewImage(imageview,"usermedia/pp/" + session.getValue("id"));
            }
        }
    } catch (JSONException E) {
        e.printStackTrace();
    }

    arrayPolls = new ArrayList<>();
    getList();

    //listeners here

    return rootView;
}

然后第二个主要函数叫做“getList()”：

public void getList() {
    Network netwok = new Network(getActivity());
    Session session = new Session(getActivity());

    String resp = netwok.POST("{\"token\":\""+session.getValue("token")+"\","+
            "\"get\":\"true\""+"}","mypoll.PHP");

    try {
        JSONObject obj = new JSONObject(resp);
        JSONArray arr = obj.getJSONArray("data");

        if(obj.get("status").equals("false")) {
            return;
        }

        arrayPolls.clear();

        for(int i=0; i<arr.length(); i++) {
            JSONObject ot = arr.getJSONObject(i);
            PollItem tmp = new PollItem(ot.geTint("ID"),ot.geTint("userid"),ot.getString("description"),ot.getString("username"));
            arrayPolls.add(tmp);
        }
    }
    catch (JSONException E) {
        e.printStackTrace();
    }

    ListView list_poll_item = (ListView) rootView.findViewById(R.id.list_friend_poll);
    PollOverviewItemAdapter adapter = new PollOverviewItemAdapter(getActivity(),arrayPolls,tab_profile.this,imageview);
    list_poll_item.setAdapter(adapter);
    list_poll_item.setOnItemClickListener(this);
}

我的查询是由这个Async发送的.功能：

private class POST_requEST extends AsyncTask<String,Integer,String>{
    protected String doInBACkground(String... params) {
        String line;
        try {  
            DefaulthttpClient httpClient = new DefaulthttpClient();
            httpPost httpPost = new httpPost(params[0]);

            ArrayList<NameValuePair> postParameters;
            postParameters = new ArrayList<>();

            postParameters.add(new BasicNameValuePair("json",query));

            httpPost.setEntity(new UrlEncodedFormEntity(postParameters));

            httpResponse httpResponse = httpClient.execute(httpPost);
            httpentity httpentity = httpResponse.getEntity();
            line = EntityUtils.toString(httpentity);

        } catch (UnsupportedEncodingException E) {
            line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
        } catch (MalformedURLException E) {
            line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
        } catch (IOException E) {
            line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
        }
        return line;
    }

    protected void onPostExecute(String result) {
        super.onPostExecute(result);
    }
}

和最后一个功能：

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

      public DownloadImageTask(ImageView bmImagE) {
          this.bR_483_11845@Image = 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);
      }
}

所以我认为这些是我的代码的重要部分.我真的希望找到解决这个问题的方法.我已经多次尝试加载我的UI,然后加载来自服务器的数据,但它是相同的.我通过使用“onStart()”尝试了这个.

提前致谢… ：-)