Android 重新启动加载程序调用时出错
我有一个片段，它将数据加载到列表适配器中以显示在屏幕上。当我的应用程序启动时，它会启动一个服务来寻找新的数据，如果找到了这些数据，片段将需要显示出来。目前，我的私人广播接收器实际上是在主要活动上，而不是片段上。这对我来说似乎不正确，但我看不出如何将来自广播接收器的通知在片段本身上传递回片段，我读到的另一个问题是建议这种方法 通过下面我发布的代码，当我的广播接收器收到一个通知并调用片段上的UpdateContent时，我得到了一个结果-我记录了以下错误：Android 重新启动加载程序调用时出错,android,Android,我有一个片段，它将数据加载到列表适配器中以显示在屏幕上。当我的应用程序启动时，它会启动一个服务来寻找新的数据，如果找到了这些数据，片段将需要显示出来。目前，我的私人广播接收器实际上是在主要活动上，而不是片段上。这对我来说似乎不正确，但我看不出如何将来自广播接收器的通知在片段本身上传递回片段，我读到的另一个问题是建议这种方法 通过下面我发布的代码，当我的广播接收器收到一个通知并调用片段上的UpdateContent时，我得到了一个结果-我记录了以下错误： 10-26 20:31:21.328: E
10-26 20:31:21.328: E/AndroidRuntime(711): FATAL EXCEPTION: main
10-26 20:31:21.328: E/AndroidRuntime(711): java.lang.RuntimeException: Error receiving broadcast Intent { act=updatedata flg=0x10 (has extras) } in com.thedailydigi.dailydigi.Main$1@41458418
10-26 20:31:21.328: E/AndroidRuntime(711): at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:765)
10-26 20:31:21.328: E/AndroidRuntime(711): at android.os.Handler.handleCallback(Handler.java:615)
10-26 20:31:21.328: E/AndroidRuntime(711): at android.os.Handler.dispatchMessage(Handler.java:92)
10-26 20:31:21.328: E/AndroidRuntime(711): at android.os.Looper.loop(Looper.java:137)
10-26 20:31:21.328: E/AndroidRuntime(711): at android.app.ActivityThread.main(ActivityThread.java:4745)
10-26 20:31:21.328: E/AndroidRuntime(711): at java.lang.reflect.Method.invokeNative(Native Method)
10-26 20:31:21.328: E/AndroidRuntime(711): at java.lang.reflect.Method.invoke(Method.java:511)
10-26 20:31:21.328: E/AndroidRuntime(711): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-26 20:31:21.328: E/AndroidRuntime(711): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-26 20:31:21.328: E/AndroidRuntime(711): at dalvik.system.NativeStart.main(Native Method)
10-26 20:31:21.328: E/AndroidRuntime(711): Caused by: java.lang.IllegalStateException: There is already a listener registered
10-26 20:31:21.328: E/AndroidRuntime(711): at android.support.v4.content.Loader.registerListener(Loader.java:130)
10-26 20:31:21.328: E/AndroidRuntime(711): at android.support.v4.app.LoaderManagerImpl$LoaderInfo.start(LoaderManager.java:260)
10-26 20:31:21.328: E/AndroidRuntime(711): at android.support.v4.app.LoaderManagerImpl.installLoader(LoaderManager.java:510)
10-26 20:31:21.328: E/AndroidRuntime(711): at android.support.v4.app.LoaderManagerImpl.createAndInstallLoader(LoaderManager.java:497)
10-26 20:31:21.328: E/AndroidRuntime(711): at android.support.v4.app.LoaderManagerImpl.restartLoader(LoaderManager.java:643)
10-26 20:31:21.328: E/AndroidRuntime(711): at com.thedailydigi.dailydigi.activity.HorizontalListFragment.updateContent(HorizontalListFragment.java:130)
10-26 20:31:21.328: E/AndroidRuntime(711): at com.thedailydigi.dailydigi.Main$1.onReceive(Main.java:36)
10-26 20:31:21.328: E/AndroidRuntime(711): at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:755)
public class Main extends FragmentActivity {
private static final String LOG_TAG = "dd-Main";
private HorizontalListFragment mDailyDigiFragment;
private BroadcastReceiver myReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
//TODO go update the UI from the database
int newRecords = intent.getIntExtra(DownloadFeedService.DOWNLOADED,0);
long date = intent.getLongExtra(DownloadFeedService.BEGIN_DATE, DownloadFeedService.NULL_DATE);
Log.d(LOG_TAG, newRecords + " new records downloaded!");
if (intent.getStringExtra(DownloadFeedService.KEY).equals(getString(R.string.daily_digi_short))) {
mDailyDigiFragment.updateContent(newRecords, date);
} else {
//TODO add our other fragments here
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.v(LOG_TAG, "Main Activity started");
registerReceiver(myReceiver, new IntentFilter(DownloadFeedService.UPDATEDATA));
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
//mDailyDigiFragment = HorizontalListFragment.newInstance(getString(R.string.daily_digi_short), 10, R.drawable.banner_dailydigi, true);
mDailyDigiFragment = HorizontalListFragment.newInstance(getString(R.string.daily_digi_short), 10, R.drawable.banner_dailydigi, true);
FragmentTransaction dailyDigiTransaction = getSupportFragmentManager().beginTransaction();
dailyDigiTransaction.add(R.id.dailydigi, mDailyDigiFragment).commit();
//TODO instantiate our other fragments here
/*
Fragment digiShowFragment = HorizontalListFragment.newInstance(getString(R.string.digi_show_short), 10, R.drawable.banner_digishow, true);
FragmentTransaction digiShowTransaction = getSupportFragmentManager().beginTransaction();
digiShowTransaction.add(R.id.digishow, digiShowFragment).commit();*/
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
public class HorizontalListFragment extends Fragment
implements LoaderManager.LoaderCallbacks<ArrayList<RssFeed.Article>> {
private ArticleAdapter adapter ;
private static final String LOG_TAG = "dd-HorizontalListFragment";
private static String MAX_LOAD_KEY = "max";
private static String DATASOURCE_KEY = "key";
private static String IMAGE_SRC_KEY = "image";
private static String SHOW_TEXT_OVERLAY = "showOverlay";
private String mRssFeedKey = "";
private int mDefaultLoad;
private int mImageResource = 0;
//TODO do we want to toggle the overlay on the digishow feed?
private boolean mShowTextOverlay = true;
private HorizontalListView mListView;
ArticleLoader mLoader;
public static HorizontalListFragment newInstance(String key, int max, int img, boolean showOverlay) {
HorizontalListFragment myFragment = new HorizontalListFragment();
Bundle args = new Bundle();
args.putString(DATASOURCE_KEY, key);
args.putInt(MAX_LOAD_KEY, max);
args.putInt(IMAGE_SRC_KEY, img);
args.putBoolean(SHOW_TEXT_OVERLAY, showOverlay);
myFragment.setArguments(args);
return myFragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle bundle = this.getArguments();
mRssFeedKey = bundle.getString(DATASOURCE_KEY);
mDefaultLoad = bundle.getInt(MAX_LOAD_KEY, getResources().getInteger(R.integer.default_display_max));
mImageResource = bundle.getInt(IMAGE_SRC_KEY, 0);
mShowTextOverlay = bundle.getBoolean(SHOW_TEXT_OVERLAY, true);
mLoader = new ArticleLoader(getActivity(), mRssFeedKey,mDefaultLoad);
getActivity().getSupportLoaderManager().initLoader(0, null, this);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.horizontal_list_section, container, false);
ImageView img = (ImageView) view.findViewById(R.id.Header_Image);
img.setImageResource(mImageResource);
mListView = (HorizontalListView) view.findViewById(R.id.hr_listview);
return view;
}
@Override
public Loader<ArrayList<RssFeed.Article>> onCreateLoader(int arg0, Bundle bundle) {
Log.d(LOG_TAG, "onCreateLoader: find " + mDefaultLoad + " articles from " + mRssFeedKey);
return mLoader;
}
@Override
public void onLoadFinished(Loader<ArrayList<RssFeed.Article>> arg0, ArrayList<RssFeed.Article> result) {
Log.d(LOG_TAG, "onLoadFinished with " + result.size() + " records from " + mRssFeedKey);
//update the listview with the combined results list
if (adapter == null) {
adapter = new ArticleAdapter(this.getActivity(), result,true);
mListView.setAdapter(adapter);
} else {
insertNewArticles(result);
adapter.notifyDataSetChanged();
}
//TODO use these methods to reset the list position ?
//mListView.setSelectionFromTop(currentFirstVisibleItem, 0);
//mListView.getFirstVisiblePosition();
}
@Override
public void onLoaderReset(Loader<ArrayList<RssFeed.Article>> arg0) {
Log.v(LOG_TAG, "onLoaderReset");
// TODO what do we need to do here?
}
public void updateContent(int newRecords , long date) {
if (date == DownloadFeedService.NULL_DATE) {
Log.d(LOG_TAG, "updateContent requesting " + newRecords + " new records.");
//this is when some new recent content has been downloaded
mLoader.setDownloadParameters(newRecords, 0);
getActivity().getSupportLoaderManager().restartLoader(0, null, this);
} else {
//this was probably downloaded cuz we're scrolling near the end
}
}
//both lists should already be sorted in date desc order
private void insertNewArticles(ArrayList<RssFeed.Article> listB) {
//TODO - we need to make sure we only add new entries
int listPosition = 0;
for (Article a : listB ) {
for (int i = listPosition; i < adapter.getCount(); i++) {
Article b = adapter.getItem(i);
//already in the list - skip over it
if (a.getInternalId() == b.getInternalId()) {
listPosition = i+1;
break;
}
//our new item is published after - it shows at the front of the list
if (a.getPublicationDate().before(b.getPublicationDate())) {
adapter.insert(a, i-1);
listPosition = i;
break;
}
}
//when we get to new items that pre-date our current list items, add them at the end
if (listPosition == adapter.getCount()) {
adapter.insert(a, listPosition);
listPosition++;
}
}
}
}
公共类HorizontaListFragment扩展了片段
实现LoaderManager.LoaderCallbacks{
专用适配器；
私有静态最终字符串LOG_TAG=“dd HorizontalListFragment”；
私有静态字符串MAX\u LOAD\u KEY=“MAX”；
私有静态字符串数据源\u KEY=“KEY”；
私有静态字符串IMAGE\u SRC\u KEY=“IMAGE”；
私有静态字符串SHOW\u TEXT\u OVERLAY=“showOverlay”；
私有字符串mRssFeedKey=“”；
私有int-mDefaultLoad；
私有int-mimagerource=0；
//我们想在digishow提要上切换覆盖吗？
私有布尔值mShowTextOverlay=true；
私有水平视图；
装载机；
公共静态HorizontaListFragment newInstance（字符串键、int max、int img、布尔showOverlay）{
HorizontalListFragment myFragment=新的HorizontalListFragment（）；
Bundle args=新Bundle（）；
args.putString（数据源_键，键）；
参数putInt（最大加载键，最大值）；
args.putInt（IMAGE\u SRC\u KEY，img）；
args.putBoolean（显示文本覆盖，显示覆盖）；
myFragment.setArguments（args）；
返回myFragment；
}
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
Bundle=this.getArguments（）；
mRssFeedKey=bundle.getString（数据源\ U键）；
mDefaultLoad=bundle.getInt（最大加载键，getResources（）.getInteger（R.integer.default\u display\u MAX））；
mimagerource=bundle.getInt（IMAGE\u SRC\u键，0）；
mShowTextOverlay=bundle.getBoolean（SHOW_TEXT_OVERLAY，true）；
mLoader=newarticleloader（getActivity（），mRssFeedKey，mDefaultLoad）；
getActivity（）.getSupportLoaderManager（）.initLoader（0，null，this）；
}
@凌驾
已创建ActivityState上的公共无效（Bundle savedInstanceState）{
super.onActivityCreated（savedInstanceState）；
}
@凌驾
CreateView上的公共视图（布局、充气机、视图组容器、捆绑包保存状态）{
视图=充气机。充气（右布局。水平列表部分，容器，假）；
ImageView img=（ImageView）view.findViewById（R.id.Header\u Image）；
img.setImageResource（miImageResource）；
mListView=（HorizontalListView）view.findViewById（R.id.hr\u列表视图）；
返回视图；
}
@凌驾
公共加载器onCreateLoader（int arg0，Bundle）{
Log.d（Log_标签，“onCreateLoader:从“+mRssFeedKey”中查找“+mDefaultLoad+”文章）；
返回式装载机；
}
@凌驾
public void onLoadFinished（加载程序arg0，ArrayList结果）{
Log.d（Log_标记，“onLoadFinished with”+result.size（）+“记录来自”+mRssFeedKey）；
//使用组合结果列表更新listview
if（适配器==null）{
adapter=newarticleAdapter（this.getActivity（），result，true）；
mListView.setAdapter（适配器）；
}否则{
插入新文章（结果）；
adapter.notifyDataSetChanged（）；
}
//如何使用这些方法重置列表位置？
//mListView.setSelectionFromTop（currentFirstVisibleItem，0）；
//mListView.getFirstVisiblePosition（）；
}
@凌驾
公共void onLoaderReset（加载程序arg0）{
Log.v（Log_标签，“onLoaderReset”）；
//TODO我们需要在这里做什么？
}
public void updateContent（int newRecords，长日期）{
if（date==DownloadFeedService.NULL\u日期）{
Log.d（Log_标签，“updateContent请求”+newRecords+“newRecords”）；
//这是最近下载的一些新内容
设置下载参数（newRecords，0）；
getActivity（）.getSupportLoaderManager（）.restartLoader（0，null，this）；
}否则{
//这可能是下载的，因为我们正在滚动接近尾声
}
}
//这两个列表应该已经按日期描述顺序排序
私有void insertNewArticles（ArrayList listB）{
//TODO-我们需要确保只添加新条目
int listPosition=0；
（a条：清单B）{
for（int i=listPosition；ipublic class ArticleLoader extends AsyncTaskLoader<ArrayList<RssFeed.Article>> {
private static final String LOG_TAG = "dd-ArticleLoader";
ArrayList<RssFeed.Article> mArticles;
final String mSource;
int mOffset = 0;
int mDownloadCount;
public ArticleLoader(Context context, String source, int max) {
super(context);
mSource = source;
mDownloadCount = max;
}
public void setDownloadParameters(int count, int offset) {
mOffset = offset;
mDownloadCount = count;
}
/**
* This is where the bulk of our work is done. This function is
* called in a background thread and should generate a new set of
* data to be published by the loader.
*/
@Override public ArrayList<RssFeed.Article> loadInBackground() {
Log.d(LOG_TAG, "loadInBackground: find " + mDownloadCount + " articles from " + mSource);
mArticles = ArticleManager.findArticles(getContext().getContentResolver(), mSource, mDownloadCount, mOffset);
return mArticles;
}
@Override
protected void onStartLoading() {
if(mArticles != null) {
deliverResult(mArticles);
} else {
forceLoad();
}
}
}
@Override
public Loader<ArrayList<RssFeed.Article>> onCreateLoader(int arg0, Bundle bundle) {
Log.d(LOG_TAG, "onCreateLoader: find " + mDefaultLoad + " articles from " + mRssFeedKey);
return mLoader;
}
@Override
public Loader<ArrayList<RssFeed.Article>> onCreateLoader(int arg0, Bundle bundle) {
Log.d(LOG_TAG, "onCreateLoader: find " + mDefaultLoad + " articles from " + mRssFeedKey);
return new ArticleLoader(getActivity(), mRssFeedKey,mDefaultLoad);
}