Android 如何在片段中实现无休止的listview？

我正在片段中实现无限的listview。当我为我的listview编写

setOnScrollListener

的代码时，我的应用程序因错误

而崩溃，适配器的内容已更改，但listview未收到通知。确保适配器的内容不是从后台线程修改的，而是仅从UI线程修改的。确保您的适配器在其内容更改时调用notifyDataSetChanged（）。

我已经尝试了几乎所有的方法在我的适配器上应用了

notifyDataSetChanged（）

。请帮我解决这个问题

下面是我的代码

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View rootView = inflater.inflate(R.layout.fragment_all_campaign, container, false);
        allCampaignList = (ListView) rootView.findViewById(R.id.allCampaignList);
        adapter = new CampaignListAdapter(getActivity(), CampaignDataArrayList);
        loadCampaignsData(offsetValue);

        allCampaignList.setOnScrollListener(new AbsListView.OnScrollListener() {

            @Override
            public void onScroll(AbsListView view,
                                 int firstVisibleItem, int visibleItemCount,
                                 int totalItemCount) {
                //Algorithm to check if the last item is visible or not
                final int lastItem = firstVisibleItem + visibleItemCount;
                if (lastItem == totalItemCount) {
                    // you have reached end of list, load more data
                    loadCampaignsData(offsetValue + 1);
                    offsetValue++;
                }
            }

            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {
                //blank, not using this
            }
        });

        return rootView;
    }

下面是LoadActivityData（）的方法：

下面是为获取webservice而编写的asynctask

private class GetAllCampaign extends AsyncTask<String, Void, ArrayList<HashMap<String, String>>> {

        @Override
        protected ArrayList<HashMap<String, String>> doInBackground(String... params) {
            try {
                HttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(Constants.DADAMI_URL + Constants.ALL_CAMPAIGN);

                List<NameValuePair> list = new ArrayList<NameValuePair>();
                list.add(new BasicNameValuePair("cat_id", "0"));
                list.add(new BasicNameValuePair("user_id", ""));
                list.add(new BasicNameValuePair("offset", params[0]));

                httpPost.setEntity(new UrlEncodedFormEntity(list));
                HttpResponse httpResponse = httpClient.execute(httpPost);

                HttpEntity httpEntity = httpResponse.getEntity();
                return readResponse(httpResponse);
                //return null;
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
            super.onPostExecute(result);
            hideDialog();
            if (result == null) {
                Toast.makeText(context, "Something went wrong.. Please try again..!!", Toast.LENGTH_LONG).show();
            } else {
                getActivity().runOnUiThread(new Runnable() {
                    public void run() {

                        allCampaignList.setAdapter(adapter);

                    }
                });


            }
        }
    }

    private ArrayList<HashMap<String, String>> readResponse(HttpResponse res) {
        InputStream is = null;
        try {
            is = res.getEntity().getContent();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
            StringBuffer sb = new StringBuffer();
            String line = "";
            while ((line = bufferedReader.readLine()) != null) {
                sb.append(line);
            }

            JSONObject mainObj = new JSONObject(sb.toString());
            JSONArray fundraiser_data = null;

            fundraiser_data = mainObj.getJSONArray("fundraiser_data");

            for (int i = 0; i < fundraiser_data.length(); i++) {
                JSONObject elem = fundraiser_data.getJSONObject(i);

                String fundraiser_photo = elem.getString("fundraiser_photo");
                String title = elem.getString("title");
                String fullname = elem.getString("fullname");


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

                campaignData.put("fundraiser_photo", Constants.DADAMI_IMAGE_URL + fundraiser_photo);
                campaignData.put("title", title);
                campaignData.put("fullname", fullname);


                CampaignDataArrayList.add(campaignData);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return CampaignDataArrayList;

    }

私有类GetAllCampaign扩展异步任务{
@凌驾
受保护的ArrayList doInBackground（字符串…参数）{
试一试{
HttpClient HttpClient=新的DefaultHttpClient（）；
HttpPost HttpPost=新的HttpPost（Constants.DADAMI_URL+Constants.ALL_活动）；
列表=新的ArrayList（）；
添加（新的BasicNameValuePair（“类别id”，“0”）；
添加（新的BasicNameValuePair（“用户id”）；
添加（新的BasicNameValuePair（“偏移量”，参数[0]）；
setEntity（新的UrlEncodedFormEntity（列表））；
HttpResponse HttpResponse=httpClient.execute（httpPost）；
HttpEntity HttpEntity=httpResponse.getEntity（）；
返回readResponse（httpResponse）；
//返回null；
}捕获（异常）{
异常。printStackTrace（）；
}
返回null；
}
@凌驾
受保护的void onPostExecute（ArrayList结果）{
super.onPostExecute（结果）；
hideDialog（）；
如果（结果==null）{
Toast.makeText（上下文，“出现问题..请重试..！！”，Toast.LENGTH_LONG.show（）；
}否则{
getActivity（）.runOnUiThread（新的Runnable（））{
公开募捐{
AllActivityList.setAdapter（适配器）；
}
});
}
}
}
专用ArrayList readResponse（HttpResponse res）{
InputStream=null；
试一试{
is=res.getEntity（）.getContent（）；
BufferedReader BufferedReader=新的BufferedReader（新的InputStreamReader（is））；
StringBuffer sb=新的StringBuffer（）；
字符串行=”；
而（（line=bufferedReader.readLine（））！=null）{
某人附加（行）；
}
JSONObject mainObj=新的JSONObject（sb.toString（））；
JSONArray筹款人_data=null；
募捐者数据=mainObj.getJSONArray（“募捐者数据”）；
对于（int i=0；i

使用Recyclerview以更好地接近

处理程序中的所有代码必须在UI线程中运行，您可以使用
runOnUIThread
或使用
新处理程序（Looper.getMainLooper（））创建处理程序对象使处理程序成为UI处理程序
private class GetAllCampaign extends AsyncTask<String, Void, ArrayList<HashMap<String, String>>> {

        @Override
        protected ArrayList<HashMap<String, String>> doInBackground(String... params) {
            try {
                HttpClient httpClient = new DefaultHttpClient();
                HttpPost httpPost = new HttpPost(Constants.DADAMI_URL + Constants.ALL_CAMPAIGN);

                List<NameValuePair> list = new ArrayList<NameValuePair>();
                list.add(new BasicNameValuePair("cat_id", "0"));
                list.add(new BasicNameValuePair("user_id", ""));
                list.add(new BasicNameValuePair("offset", params[0]));

                httpPost.setEntity(new UrlEncodedFormEntity(list));
                HttpResponse httpResponse = httpClient.execute(httpPost);

                HttpEntity httpEntity = httpResponse.getEntity();
                return readResponse(httpResponse);
                //return null;
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
            super.onPostExecute(result);
            hideDialog();
            if (result == null) {
                Toast.makeText(context, "Something went wrong.. Please try again..!!", Toast.LENGTH_LONG).show();
            } else {
                getActivity().runOnUiThread(new Runnable() {
                    public void run() {

                        allCampaignList.setAdapter(adapter);

                    }
                });


            }
        }
    }

    private ArrayList<HashMap<String, String>> readResponse(HttpResponse res) {
        InputStream is = null;
        try {
            is = res.getEntity().getContent();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
            StringBuffer sb = new StringBuffer();
            String line = "";
            while ((line = bufferedReader.readLine()) != null) {
                sb.append(line);
            }

            JSONObject mainObj = new JSONObject(sb.toString());
            JSONArray fundraiser_data = null;

            fundraiser_data = mainObj.getJSONArray("fundraiser_data");

            for (int i = 0; i < fundraiser_data.length(); i++) {
                JSONObject elem = fundraiser_data.getJSONObject(i);

                String fundraiser_photo = elem.getString("fundraiser_photo");
                String title = elem.getString("title");
                String fullname = elem.getString("fullname");


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

                campaignData.put("fundraiser_photo", Constants.DADAMI_IMAGE_URL + fundraiser_photo);
                campaignData.put("title", title);
                campaignData.put("fullname", fullname);


                CampaignDataArrayList.add(campaignData);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return CampaignDataArrayList;

    }