本文介绍了在扩展片段使用ListAdapter失败的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我试图JSON数据更新到ListView控件。它使用ListAdapter时失败。是片段剪掉允许？我坚持要使用的延伸片段。是否有任何方法？
I trying to update the JSON data into ListView. It failed when using ListAdapter. Is fragment didnt allow that ? I insist want to use the extends Fragment. Is there any method on that ?
请帮助我。谢谢你。
下面是整个code的一部分。
Here is part of the whole code.
public class ScheduleFragment extends Fragment {
public ProgressDialog pDialog;
private ListView myListView;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> subjectList;
// url to get all subjects list
private static String url_all_subjects = "http://192.168.1.12/android_project/get_subjects.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_STUDENT = "students";
private static final String TAG_MATRIX_ID = "matrix";
private static final String TAG_NAME = "name";
// subject JSONArray
JSONArray subject = null;
public ScheduleFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.fragment_schedule, container, false);
//------------------------------------CREATING A LISTVIEW-----------------------
// Loading subject in Background Thread
new LoadAllSubject().execute();
// Hashmap for ListView
subjectList = new ArrayList<HashMap<String, String>>();
myListView = (ListView) rootView.findViewById(R.id.textViewMatrix);
// on selecting single subject
myListView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String matrix_id = ((TextView) view.findViewById(R.id.textViewMatrix)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getActivity().getApplicationContext(),
SingleSubject.class);
// sending matrix id to next activity
in.putExtra(TAG_MATRIX_ID, matrix_id);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
return rootView;
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllSubject extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = ProgressDialog.show(ScheduleFragment.this.getActivity(), "Progress", "Loading subjects. Please wait...", false);
//pDialog.setMessage("Loading subjects. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_subjects, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Subject
subject = json.getJSONArray(TAG_STUDENT);
// looping through All Subjects
for (int i = 0; i < subject.length(); i++) {
JSONObject c = subject.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_MATRIX_ID);
String name = c.getString(TAG_NAME);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_MATRIX_ID, id);
map.put(TAG_NAME, name);
// adding HashList to ArrayList
subjectList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
getActivity(), subjectList,
R.layout.all_subject, new String[] { TAG_MATRIX_ID,
TAG_NAME},
new int[] { R.id.matrix_id, R.id.name });
// updating listview
myListView.setListAdapter(adapter);
}
}
}
}
这是all_subject.xml
This is all_subject.xml
<!-- Subject matrix_id - will be HIDDEN - used to pass to other activity -->
<TextView
android:id="@+id/matrix_id"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<!-- Name Label -->
<TextView
android:id="@+id/name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingTop="6dip"
android:paddingLeft="6dip"
android:textSize="17dip"
android:textStyle="bold" />
推荐答案
您需要延长 ListFramgent 。 setListAdapter 是 ListFragment 的方法。
You need to extend ListFramgent. setListAdapter is a method of ListFragment.
没有必要使用 runOnUiThread 。 onPostExecute 调用UI线程上。
No need to use runOnUiThread. onPostExecute is invoked on the ui thread.
编辑：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.fragment_schedule, container, false);
subjectList = new ArrayList<HashMap<String, String>>();
myListView = (ListView) rootView.findViewById(R.id.textViewMatrix);
new LoadAllSubject().execute();
myListView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
String matrix_id = ((TextView) view.findViewById(R.id.textViewMatrix)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getActivity().getApplicationContext(),
SingleSubject.class);
// sending matrix id to next activity
in.putExtra(TAG_MATRIX_ID, matrix_id);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
return rootView;
}
然后
protected void onPostExecute(String file_url) {
super.onPostExecute(file_url);
pDialog.dismiss();
ListAdapter adapter = new SimpleAdapter(
getActivity(), subjectList,
R.layout.all_subject, new String[] { TAG_MATRIX_ID,
TAG_NAME},
new int[] { R.id.matrix_id, R.id.name });
myListView.setAdapter(adapter);
}
这篇关于在扩展片段使用ListAdapter失败的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！