AsyncTask更新适配器内容但不更新列表视图。所有代码都运行正常，但是当我更新我的适配器时，我的listview没有反映适配器的任何更新。我也搜索了谷歌这个问题，但没有找到任何适当的解决方案。它显示如下例外： -
java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification.
这是我的代码，请看看我应该改变什么： -
public class SearchResultScreen extends Fragment {
ListView searchResult;
SearchResultAdapter adapter;
TextView total_jobs,displaying_jobs;
int currentPage=0,threshold=10;
ProgressDialog progress;
JobService jobService;
TextView load_more_jobs;
int flag = 0;
public SearchResultScreen(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.search_result_screen, container, false);
searchResult = (ListView) rootView.findViewById(R.id.search_result);
jobService = new JobService();
jobService.setCurrent_page(currentPage);
load_more_jobs = new TextView(getActivity());
load_more_jobs.setText("Load More Jobs");
load_more_jobs.setGravity(Gravity.CENTER_HORIZONTAL);
load_more_jobs.setPadding(5,5,5,5);
load_more_jobs.setBackgroundColor(Color.GRAY);
Map params = new HashMap();
params.put("skills", getArguments().getString("skills"));
params.put("exp_from", getArguments().getString("exp_from"));
params.put("exp_to", getArguments().getString("exp_to"));
params.put("location", getArguments().getString("location"));
params.put("func_area", getArguments().getString("functional_area"));
params.put("start", jobService.getCurrent_page());
total_jobs = (TextView) rootView.findViewById(R.id.total_jobs_label);
displaying_jobs = (TextView) rootView.findViewById(R.id.displaying_jobs);
progress = new ProgressDialog(getActivity());
progress.setTitle("Please Wait!!");
progress.setMessage("Wait!!");
progress.setCancelable(false);
progress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
new MyAsyncTask(params, progress, searchResult, getActivity(), jobService, total_jobs, displaying_jobs, load_more_jobs, flag, adapter).execute("rest/search_jobs.rest");
currentPage++;
load_more_jobs.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(currentPage < jobService.getTotal_page()) {
jobService.setCurrent_page(currentPage);
Map params = new HashMap();
params.put("skills", getArguments().getString("skills"));
params.put("exp_from", getArguments().getString("exp_from"));
params.put("exp_to", getArguments().getString("exp_to"));
params.put("location", getArguments().getString("location"));
params.put("func_area", getArguments().getString("functional_area"));
params.put("start", jobService.getCurrent_page());
flag = 1;
new MyAsyncTask(params, progress, searchResult, getActivity(), jobService, total_jobs, displaying_jobs, load_more_jobs, flag, adapter).execute("rest/search_jobs.rest");
currentPage++;
}
}
});
searchResult.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
JobSearchModel jobs = (JobSearchModel) adapterView.getItemAtPosition(i);
FragmentManager fragmentManager = getFragmentManager();
Fragment search_result_screen = new SearchResultScreen();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
JobDescription jobDescription = new JobDescription();
Bundle args = new Bundle();
args.putSerializable("jobs", jobs);
jobDescription.setArguments(args);
fragmentTransaction.replace(R.id.content_frame, jobDescription);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
//Toast.makeText(getActivity(), "Id is : " + jobs.getJob_id(), Toast.LENGTH_LONG).show();
}
});
return rootView;
}
static class MyAsyncTask extends AsyncTask<String, Integer, String> {
private Map params;
private ProgressDialog progress;
private ListView list;
private Activity context;
private JobService jobService;
private TextView total_jobs;
private TextView displaying_jobs;
private TextView load_more_jobs;
private int flag;
private SearchResultAdapter adapter;
Object[] object_response;
public MyAsyncTask(Map params, ProgressDialog progress, ListView searchResult, Activity context, JobService jobService, TextView total_jobs, TextView displaying_jobs, TextView load_more_jobs, int flag, SearchResultAdapter adapter) {
this.params = params;
this.progress = progress;
this.list = searchResult;
this.context = context;
this.jobService = jobService;
this.total_jobs = total_jobs;
this.displaying_jobs = displaying_jobs;
this.load_more_jobs = load_more_jobs;
this.flag = flag;
this.adapter = adapter;
}
@Override
public void onPreExecute() {
this.progress.show();
}
public void onProgressUpdate(Integer filesDownloaded) {
}
protected String doInBackground(String... parameters) {
postData(parameters[0]);
return "done";
}
protected void onPostExecute(String result){
context.runOnUiThread(new Runnable() {
@Override
public void run() {
if(flag == 0) {
adapter = new SearchResultAdapter(context, jobService.getModel(object_response));
list.addFooterView(load_more_jobs, null, false);
list.setAdapter(adapter);
} else {
adapter = new SearchResultAdapter(context, jobService.getModel(object_response));
}
total_jobs.setText(""+jobService.getTotal_jobs());
displaying_jobs.setText(""+jobService.displayingJobs());
}
});
adapter.notifyDataSetChanged();
this.progress.dismiss();
}
protected void onProgressUpdate(String progress){
}
public void postData(final String request) {
RestTemplate restTemplate = new RestTemplate();
restTemplate.getMessageConverters().add(new StringHttpMessageConverter());
object_response = restTemplate.postForObject(UtilClass.baseURL+request, params, JobSearchModel[].class);
}
}
}
答案 0 :(得分：1)
您可以在添加以下行
时修复错误adpater.notifyDataSetChanged();
当列表更改时，您必须调用上述函数。
注意：确保在UI线程中调用notifyDataSetChanged()。
答案 1 :(得分：0)
例外是：
java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification.
因此您需要通知listview，适配器数据已更改。
致电
listView.invalidateViews();
adapter.notifyDataSetChanged();
希望它有所帮助。