我正在构建一个基本应用程序，它在列表视图中显示数据库中的数据。哪个工作正常，我决定使用导航抽屉添加一个滑动菜单哪个使用扩展到片段的活动所以我一直在改变我的所有类扩展片段所以他们可以添加到新的导航菜单。 我的问题是：在我的一个班级 AllBarsActivity 中我添加了一个显示数据库数据的列表，为此， AllBarsActivity 扩展 ListActivity 。 我的导航系统使用扩展到片段的类，我这样做，所以现在我收到错误。我的问题是如何在片段中添加列表视图。 在尝试添加幻灯片菜单导航抽屉之前，这是我之前的内容：
public class AllBarsActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// might have to change json import///////////
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> barsList;
// url to get all products list
private static String url_all_bars = "http://www.milamboltd.freeserver.me/android_login_api/get_all_bars.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_BARS = "bars";
private static final String TAG_PID = "pid";
private static final String TAG_ARTIST = "artist";
private static final String TAG_TITLE = "title";
private static final String TAG_DESCRIPTION = "description";
private static final String TAG_CREATED_AT= "created_at";
private static final String TAG_UPLOADEDBY = "uploadedBy";
String userLoggedIn;
private static String KEY_EMAIL = "email";
// bars JSONArray
JSONArray bars = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_bars);
// getting bar details from intent
Intent i = getIntent();
// getting bar id (pid) from intent
userLoggedIn = i.getStringExtra(KEY_EMAIL);
// Hashmap for ListView
barsList = new ArrayList<HashMap<String, String>>();
// Loading bars in Background Thread
new LoadAllBars().execute();
// Get listview
ListView lv = getListView();
// on seleting single bar
// launching Edit bar Screen
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// // Starting new intent
// Intent in = new Intent(getApplicationContext(),
// EditBarActivity.class);
// // sending pid to next activity
// in.putExtra(TAG_PID, pid);
//
// starting new activity and expecting some response back
// startActivityForResult(in, 100);
}
});
}
// Response from Edit Bar Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted bar
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all bar by making HTTP Request
* */
class LoadAllBars extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AllBarsActivity.this);
pDialog.setMessage("Loading bars. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All bars 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_bars, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Bars: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// bars found
// Getting Array of bars
bars = json.getJSONArray(TAG_BARS);
// looping through All bars
for (int i = 0; i < bars.length(); i++) {
JSONObject c = bars.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String artist = c.getString(TAG_ARTIST);
String title = c.getString(TAG_TITLE);
String uploadedBy = c.getString(TAG_UPLOADEDBY);
String description = c.getString(TAG_DESCRIPTION);
String created_at = c.getString(TAG_CREATED_AT);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_ARTIST, artist);
map.put(TAG_TITLE, title);
map.put(TAG_UPLOADEDBY, uploadedBy);
map.put(TAG_DESCRIPTION, description);
map.put(TAG_CREATED_AT, created_at);
// adding HashList to ArrayList
barsList.add(map);
}
} else {
// no bars found
// Launch Add New bar Activity
Intent i = new Intent(getApplicationContext(),
NewBarActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} 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 bars
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AllBarsActivity.this, barsList,
R.layout.list_item, new String[] { TAG_PID,
TAG_TITLE,TAG_ARTIST,TAG_DESCRIPTION,TAG_UPLOADEDBY},
> new int[] { R.id.pid, R.id.title,R.id.artist, R.id.description,R.id.created_at });
> // updating listview
> setListAdapter(adapter);
> }
> });
>
> }
>
> } }
，这是我尝试将其转换为的片段类：
public class WhatsHotFragment extends Fragment {
// Progress Dialog
private ProgressDialog pDialog;
// might have to change json import///////////
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> barsList;
// url to get all products list
private static String url_all_bars = "http://www.milamboltd.freeserver.me/android_login_api/get_all_bars.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_BARS = "bars";
private static final String TAG_PID = "pid";
private static final String TAG_ARTIST = "artist";
private static final String TAG_TITLE = "title";
private static final String TAG_DESCRIPTION = "description";
private static final String TAG_CREATED_AT= "created_at";
private static final String TAG_UPLOADEDBY = "uploadedBy";
String userLoggedIn;
private static String KEY_EMAIL = "email";
// bars JSONArray
JSONArray bars = null;
public WhatsHotFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_whats_hot, container, false);
// getting bar details from intent
Intent i = getActivity().getIntent();
// getting bar id (pid) from intent
userLoggedIn = i.getStringExtra(KEY_EMAIL);
// Hashmap for ListView
barsList = new ArrayList<HashMap<String, String>>();
// Loading bars in Background Thread
new LoadAllBars().execute();
// Get listview
ListView lv = getListView();
// on seleting single bar
// launching Edit bar Screen
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// // Starting new intent
// Intent in = new Intent(getApplicationContext(),
// EditBarActivity.class);
// // sending pid to next activity
// in.putExtra(TAG_PID, pid);
//
// starting new activity and expecting some response back
// startActivityForResult(in, 100);
}
});
return rootView;
}
/**
* Background Async Task to Load all bar by making HTTP Request
* */
class LoadAllBars extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Loading bars. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All bars 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_bars, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Bars: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// bars found
// Getting Array of bars
bars = json.getJSONArray(TAG_BARS);
// looping through All bars
for (int i = 0; i < bars.length(); i++) {
JSONObject c = bars.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String artist = c.getString(TAG_ARTIST);
String title = c.getString(TAG_TITLE);
String uploadedBy = c.getString(TAG_UPLOADEDBY);
String description = c.getString(TAG_DESCRIPTION);
String created_at = c.getString(TAG_CREATED_AT);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_ARTIST, artist);
map.put(TAG_TITLE, title);
map.put(TAG_UPLOADEDBY, uploadedBy);
map.put(TAG_DESCRIPTION, description);
map.put(TAG_CREATED_AT, created_at);
// adding HashList to ArrayList
barsList.add(map);
}
} else {
// no bars found
// Launch Add New bar Activity
Intent i = new Intent(getActivity(),
NewBarFragment.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} 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 bars
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AllBarsActivity.this, barsList,
R.layout.list_item, new String[] { TAG_PID,
TAG_TITLE,TAG_ARTIST,TAG_DESCRIPTION,TAG_UPLOADEDBY},
new int[] { R.id.pid, R.id.title,R.id.artist, R.id.description,R.id.created_at });
// updating listview
setListAdapter(adapter);
}
});
}
}
}
我在这些代码行上出错： 1.它说方法getListView（）未定义类型 WhatsHotFragment
// Get listview
ListView lv = getListView();
- 并且在范围
中无法访问AllBarsActivity类型的封闭实例protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all bars
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AllBarsActivity.this, barsList,
R.layout.list_item, new String[] { TAG_PID,
TAG_TITLE,TAG_ARTIST,TAG_DESCRIPTION,TAG_UPLOADEDBY},
new int[] { R.id.pid, R.id.title,R.id.artist, R.id.description,R.id.created_at });
// updating listview
setListAdapter(adapter);
}
});
edit:
我添加了一个公共void void oncreated来添加listview但是它的内容视图尚未创建。
'public void onActivityCreated (Bundle savedInstanceState){
ListView lv = getListView();
}
'
答案 0 :(得分：0)
您可以扩展ListFragment而不是Fragment，您可以使用ListActivity中的列表功能。
http://developer.android.com/reference/android/app/ListFragment.html
如果您在片段内使用runOnUiThread，请先调用getActivity（）。
getActivity().runOnUiThread(new Runnable())