【发布时间】：2017-10-23 07:55:02
【问题描述】：
public class GithubTab extends Fragment implements AdapterView.OnItemClickListener {
ListView repoListView;
private ListAdapter adapter;
private List<RepositoryItem> repoListItems;
private List<String> repoNameList;
private List<String> userNameList;
private List<String> descriptionList;
private TextView tvData;
private static final String TAG = "Github Tab";
Button buttonHit;
TextView resultText;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.github_tab, container, false);
repoListView = (ListView) view.findViewById(R.id.repoList);
repoListItems = new ArrayList<>();
repoNameList = new ArrayList<>();
userNameList = new ArrayList<>();
descriptionList = new ArrayList<>();
adapter = new ListAdapter(getContext(), repoListItems);
repoListView.setAdapter(adapter);
tvData = (TextView) view.findViewById(R.id.tvJsonItem);
// Clickable: able to open the GitHub webpage of the re
repoListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(getContext(), "Clicked id" + view.getTag(), Toast.LENGTH_SHORT).show();
}
});
new JSONTask().execute("https://api.github.com/users/whyjay17/repos");
for(int i = 0; i < repoNameList.size(); i++) {
repoListItems.add(new RepositoryItem(i, repoNameList.get(i), userNameList.get(i), "ddd"));
}
return view;
}
public class JSONTask extends AsyncTask<String, String, String> {
@Override
// Any non-UI thread process is running in this method. After completion, it sends the result to OnPostExecute
protected String doInBackground(String... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
.... Code Hidden ....
return retreivedJson;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
//cant close null
if (connection != null) {
// close both connection and the reader
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
public void formatJSONArray(String results){
try {
JSONArray jsonArray = new JSONArray(results);
for(int i = 0; i < jsonArray.length(); i++){
JSONObject jsonObject=jsonArray.getJSONObject(i);
if(jsonObject.optString("name") != null) {
//tvData.append(jsonObject.getString("name"));
repoNameList.add(jsonObject.getString("name"));
//Toast.makeText(getContext(), "1 " + repoNameList.get(1), Toast.LENGTH_SHORT).show();
}
if(jsonObject.optJSONObject("owner") != null){
JSONObject ownerObject=jsonObject.getJSONObject("owner");
if(ownerObject.optString("login")!=null) {
//tvData.append(ownerObject.getString("login"));
userNameList.add(ownerObject.getString("login"));
//ownerObject.append(ownerObject.getString("avatar_url"));
}
}
}
}catch (JSONException jsonException){
}
}
/*
* Called after the background computation finishes. Result of doInBackground is passed in as a parameter.
*
* */
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
/* for JSONArray data*/
if(result!=null && !result.isEmpty()) {
formatJSONArray(result);
}
}
}
}
上面的代码基本上试图解析来自https://api.github.com/users/famous/repos 的 JSON 数据，将一些特定信息（repo 名称、id、描述）添加到相应的列表中，并尝试在我创建的 listView 上显示这些信息。
当我对信息进行硬编码时（意味着 listView 本身没有问题），listView 工作，但是当我尝试将数据放入列表中时（其中包含解析的 JSON 信息，我测试它是实际上在列表中），它给了我一个空列表。
我怎样才能做到这一点？
【问题讨论】：
-
添加新元素后，您是否为您的适配器调用了
notifyDataSetChanged()？