我如何刷新列表片段？没有来自网络的教程 :( 我不知道如何重新加载这个 listfragment。我尝试通过 transaktionmanager 重新加载，但它与 ActionBar.TabListener 发生冲突，这不是 support.v4。我如何从 loadermanager 检索新数据并更新 listfragment？
活动：
package sk.test;
import android.app.ActionBar;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.app.FragmentTransaction;
import android.support.v4.app.LoaderManager;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
import java.util.List;
import java.util.Locale;
import sk.test.frags.TodoFragment;
import sk.test.prefs.EditPreferences;
import sk.test.task.DataListLoader;
import sk.test.xml.Item;
public class MainActivity extends FragmentActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
private TodoFragment todoFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// TODO Auto-generated method stub
switch (item.getItemId()) {
case R.id.action_settings:
startActivity(new Intent(getApplicationContext(), EditPreferences.class));
return true;
case R.id.refresh:
//HERE CODE FOR RELOAD todoFragment.reloadData() ????
return true;
default:
return true;
}
}
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
private boolean wantDone = false;
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
todoFragment = new TodoFragment();
this.wantDone = position == 0 ? false : true;
Bundle args = new Bundle();
args.putBoolean(TodoFragment.TASK_TYPE, this.wantDone);
todoFragment.setArguments(args);
return todoFragment;
}
@Override
public int getCount() {
return 2;
}
public boolean getWantDone(){
return this.wantDone;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.todotask_planned).toUpperCase(l);
case 1:
return getString(R.string.todotask_done).toUpperCase(l);
}
return null;
}
}
}
列表片段：
package sk.test;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.Loader;
import android.util.Log;
import android.view.View;
import android.widget.ListView;
import java.util.List;
import sk.test.adapter.CustomArrayAdapter;
import sk.test.task.DataListLoader;
import sk.test.xml.Item;
/**
* Created by Peter on 29.7.2013.
*/
public class TodoFragment extends ListFragment implements LoaderManager.LoaderCallbacks<List<Item>> {
public static String TASK_TYPE = "taskType";
private static final String XML_SOURCE = "http://******/";
private boolean wantDone = false;
CustomArrayAdapter mAdapter;
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Log.i("TODOLIST", "DataListFragment.onActivityCreated");
this.wantDone = getArguments().getBoolean(TASK_TYPE);
// Initially there is no data
setEmptyText("No Data Here");
// Create an empty adapter we will use to display the loaded data.
mAdapter = new CustomArrayAdapter(getActivity());
setListAdapter(mAdapter);
// Start out with a progress indicator.
setListShown(false);
// Prepare the loader. Either re-connect with an existing one,
// or start a new one.
getLoaderManager().initLoader(0, null, this);
setHasOptionsMenu(true);
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
// Insert desired behavior here.
Log.i("TODOLIST", "Item clicked: " + id);
}
@Override
public Loader<List<Item>> onCreateLoader(int i, Bundle bundle) {
Log.i("TODOLIST", "DataListFragment.onCreateLoader");
return new DataListLoader(getActivity(), this.wantDone);
}
@Override
public void onLoadFinished(Loader<List<Item>> listLoader, List<Item> items) {
mAdapter.setData(items);
Log.i("TODOLIST", "DataListFragment.onLoadFinished");
// The list should now be shown.
if (isResumed()) {
setListShown(true);
} else {
setListShownNoAnimation(true);
}
}
@Override
public void onLoaderReset(Loader<List<Item>> listLoader) {
}
public void reloadData(){
//UPDATE LIST.. HOW?
}
}
装载机：
package sk.test;
import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.support.v4.content.AsyncTaskLoader;
import android.util.Log;
import org.simpleframework.xml.Serializer;
import org.simpleframework.xml.core.Persister;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import sk.test.commons.Commons;
import sk.test.xml.Item;
import sk.test.xml.Response;
/**
* Created by Peter Chovan on 29.7.2013.
*/
public class DataListLoader extends AsyncTaskLoader<List<Item>> {
private List<Item> todoTasks;
private boolean wantDone;
SharedPreferences prefs;
public DataListLoader(Context context, boolean wantDone) {
super(context);
this.wantDone = wantDone;
prefs = PreferenceManager.getDefaultSharedPreferences(getContext());
}
@Override
public List<Item> loadInBackground() {
Log.i("TODOLIST", "DataListLoader.loadInBackground");
String xmlData = getXmlData(prefs.getString("service_url", "http://*****/"));
List<Item> entries = new ArrayList<Item>();
String state = wantDone ? "WANT DONE" : "WANT PLANNED";
if (xmlData != null) {
xmlData = xmlData.replaceAll("<([^/]+?)/>", "<$1> </$1>");
Serializer serializer = new Persister();
try {
Response res = serializer.read(Response.class, xmlData, false);
for (Item i : res.getItems().getItem()) {
if (i.isDone() == wantDone) {
entries.add(i);
}
}
} catch (Exception e) {
for (StackTraceElement s : e.getStackTrace()) {
Log.e("TEST serializer", s.toString());
}
}
} else {
Log.e("TODOLIST DATA", "NULL");
}
return entries;
}
public String getXmlData(String uri) {
try {
URL url = new URL(uri);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setDoOutput(true);
con.setRequestProperty("Accept", "application/xml");
Map<String, String> params = new HashMap<String, String>();
params.put("user", prefs.getString("service_login", "devel"));
params.put("pass", prefs.getString("service_password", "devel"));
params.put("class", "GetList");
OutputStreamWriter wr = new OutputStreamWriter(con.getOutputStream());
wr.write(Commons.getRequestData(params)); //add request params
wr.flush();
String xmlData = readStream(con.getInputStream());
wr.close();
con.disconnect();
return xmlData;
} catch (Exception e) {
for (StackTraceElement s : e.getStackTrace()) {
Log.e("TODOLIST", "doInBackground" + s.toString());
}
}
return null;
}
private String readStream(InputStream in) {
BufferedReader reader = null;
String result = "";
try {
reader = new BufferedReader(new InputStreamReader(in));
String line;
while ((line = reader.readLine()) != null) {
result += line + "\n";
}
return result;
} catch (IOException e) {
for (StackTraceElement s : e.getStackTrace()) {
Log.e("TODOLIST", "ReadStream || " + s.toString());
}
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
for (StackTraceElement s : e.getStackTrace()) {
Log.e("TODOLIST", "ReadStream || " + "Error while closing Reader");
}
}
}
}
return null;
}
/**
* Called when there is new data to deliver to the client. The
* super class will take care of delivering it; the implementation
* here just adds a little more logic.
*/
@Override
public void deliverResult(List<Item> listOfData) {
if (isReset()) {
// An async query came in while the loader is stopped. We
// don't need the result.
if (listOfData != null) {
onReleaseResources(listOfData);
}
}
List<Item> oldApps = listOfData;
todoTasks = listOfData;
if (isStarted()) {
// If the Loader is currently started, we can immediately
// deliver its results.
super.deliverResult(listOfData);
}
// At this point we can release the resources associated with
// 'oldApps' if needed; now that the new result is delivered we
// know that it is no longer in use.
if (oldApps != null) {
onReleaseResources(oldApps);
}
}
/**
* Handles a request to start the Loader.
*/
@Override
protected void onStartLoading() {
if (todoTasks != null) {
// If we currently have a result available, deliver it
// immediately.
deliverResult(todoTasks);
}
if (takeContentChanged() || todoTasks == null) {
// If the data has changed since the last time it was loaded
// or is not currently available, start a load.
forceLoad();
}
}
/**
* Handles a request to stop the Loader.
*/
@Override
protected void onStopLoading() {
// Attempt to cancel the current load task if possible.
cancelLoad();
}
/**
* Handles a request to cancel a load.
*/
@Override
public void onCanceled(List<Item> apps) {
super.onCanceled(apps);
// At this point we can release the resources associated with 'apps'
// if needed.
onReleaseResources(apps);
}
/**
* Handles a request to completely reset the Loader.
*/
@Override
protected void onReset() {
super.onReset();
// Ensure the loader is stopped
onStopLoading();
// At this point we can release the resources associated with 'apps'
// if needed.
if (todoTasks != null) {
onReleaseResources(todoTasks);
todoTasks = null;
}
}
/**
* Helper function to take care of releasing resources associated
* with an actively loaded data set.
*/
protected void onReleaseResources(List<Item> apps) {
}
}