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Je suis en train de mettre en œuvre la charge paresseux sur un listview dans un fragment d'onglet pour charger les éléments d'un abc de tableau. J'essaie de charger 10 éléments, puis lorsque l'utilisateur défile, les 10 éléments suivants seront chargés. Mais mon application ne fonctionne pas car je ne suis pas en mesure de passer au thread d'interface utilisateur afin de le mettre à jour (runonUithread (returnRes), ne fonctionne pas). COuld vous [s'il vous plaît jeter un oeil sur le code ci-dessous et suggérer la bonne façon de mettre en œuvre la charge paresseuse. Je vous remercie.erreur Lazy mise en œuvre de la charge
Fragment Classe:
package com.example.abe;
import java.util.ArrayList;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public class Tab1Fragment extends ListFragment {
ListView lv;
Activity act = this.getActivity();
Context ct = this.getActivity();
XMLGettersSetters data;
boolean loadingMore = false;
String abc[] = new String[50];
static int count = 0;
int itemsPerPage = 10;
ArrayList<String> myListItems;
ArrayList<String> myListItems2;
ArrayAdapter<String> adapter;
static int size = 0;
@SuppressWarnings("unused")
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if (container == null) {
return null;
}
myListItems2 = new ArrayList<String>();
adapter = new ArrayAdapter<String>(getActivity().getBaseContext(),
android.R.layout.simple_list_item_1, myListItems2);
View root = inflater.inflate(R.layout.tab_frag1_layout, container,
false);
lv = (ListView) root.findViewById(android.R.id.list);
lv.setAdapter(adapter);
return root;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
myListItems = new ArrayList<String>();
View footerView = ((LayoutInflater) this.getActivity()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(
R.layout.listfooter, null, false);
this.getListView().addFooterView(footerView);
this.setListAdapter(adapter);
for (int i = 0; i < 50; i++) {
abc[i] = "ab" + i;
}
this.getListView().setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
System.out.println(abc.length);
System.out.println(count);
int lastInScreen = firstVisibleItem + visibleItemCount;
System.out.println(lastInScreen);
if ((lastInScreen == totalItemCount) && !(loadingMore)) {
try {
Thread thread = new Thread(null, loadMoreListItems);
thread.start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
});
try {
Thread thread = new Thread(null, loadMoreListItems);
thread.start();
} catch (Exception e) {
e.printStackTrace();
}
}
private Runnable loadMoreListItems = new Runnable() {
@Override
public void run() {
loadingMore = true;
myListItems = new ArrayList<String>();
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
size = abc.length;
for (int i = 0; i < itemsPerPage; i++) {
if (count < size) {
myListItems.add(abc[count].toString());
count = count + 1;
} else {
break;
}
}
Log.i("a", "b");
try {
act.runOnUiThread(returnRes);
} catch (Exception e) {
e.printStackTrace();
}
Log.i("a", "b");
}
};
private Runnable returnRes = new Runnable() {
@Override
public void run() {
if (myListItems != null && myListItems.size() > 0) {
for (int i = 0; i < myListItems.size(); i++)
adapter.add(myListItems.get(i));
}
lv.setAdapter(adapter);
Log.i("a", "b");
adapter.notifyDataSetChanged();
Log.i("a", "b");
loadingMore = false;
}
};
}
Logcat:
01-18 18:59:21.606: I/System.out(971): 50
01-18 18:59:21.606: I/System.out(971): 0
01-18 18:59:21.606: I/System.out(971): 0
01-18 18:59:21.926: I/System.out(971): 50
01-18 18:59:21.926: I/System.out(971): 0
01-18 18:59:21.926: I/System.out(971): 1
01-18 18:59:22.257: I/System.out(971): 50
01-18 18:59:22.257: I/System.out(971): 0
01-18 18:59:22.257: I/System.out(971): 1
01-18 18:59:22.676: I/a(971): b
01-18 18:59:22.676: W/System.err(971): java.lang.NullPointerException
01-18 18:59:22.715: W/System.err(971): at com.example.abe.Tab1Fragment$1.run(Tab1Fragment.java:113)
01-18 18:59:22.936: W/System.err(971): at java.lang.Thread.run(Thread.java:1019)
01-18 18:59:22.936: I/a(971): b
classe FragmentActivity:
package com.example.abe;
import java.util.HashMap;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.view.View;
import android.widget.TabHost;
import android.widget.TabHost.TabContentFactory;
public class TabsFragmentActivity extends FragmentActivity implements
TabHost.OnTabChangeListener {
private TabHost mTabHost;
private HashMap<String, TabInfo> mapTabInfo = new HashMap<String, TabsFragmentActivity.TabInfo>();
private TabInfo mLastTab = null;
private class TabInfo {
private String tag;
private Class<?> clss;
private Bundle args;
private Fragment fragment;
TabInfo(String tag, Class<?> clazz, Bundle args) {
this.tag = tag;
this.clss = clazz;
this.args = args;
}
}
class TabFactory implements TabContentFactory {
private final Context mContext;
public TabFactory(Context context) {
mContext = context;
}
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tabs_layout);
initialiseTabHost(savedInstanceState);
if (savedInstanceState != null) {
mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab")); // set
// the
// tab
// as
// per
// the
// saved
// state
}
}
protected void onSaveInstanceState(Bundle outState) {
outState.putString("tab", mTabHost.getCurrentTabTag()); // save the tab
// selected
super.onSaveInstanceState(outState);
}
private void initialiseTabHost(Bundle args) {
mTabHost = (TabHost) findViewById(android.R.id.tabhost);
mTabHost.setup();
TabInfo tabInfo = null;
TabsFragmentActivity.addTab(this, this.mTabHost, this.mTabHost
.newTabSpec("Tab1").setIndicator("ST"), (tabInfo = new TabInfo(
"Tab1", Tab1Fragment.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
TabsFragmentActivity.addTab(this, this.mTabHost, this.mTabHost
.newTabSpec("Tab2").setIndicator("CSI"),
(tabInfo = new TabInfo("Tab2", Tab2Fragment.class, args)));
this.mapTabInfo.put(tabInfo.tag, tabInfo);
this.onTabChanged("Tab1");
mTabHost.setOnTabChangedListener(this);
}
private static void addTab(TabsFragmentActivity activity, TabHost tabHost,
TabHost.TabSpec tabSpec, TabInfo tabInfo) {
tabSpec.setContent(activity.new TabFactory(activity));
String tag = tabSpec.getTag();
tabInfo.fragment = activity.getSupportFragmentManager()
.findFragmentByTag(tag);
if (tabInfo.fragment != null && !tabInfo.fragment.isDetached()) {
FragmentTransaction ft = activity.getSupportFragmentManager()
.beginTransaction();
ft.detach(tabInfo.fragment);
ft.commit();
activity.getSupportFragmentManager().executePendingTransactions();
}
tabHost.addTab(tabSpec);
}
public void onTabChanged(String tag) {
TabInfo newTab = this.mapTabInfo.get(tag);
if (mLastTab != newTab) {
FragmentTransaction ft = this.getSupportFragmentManager()
.beginTransaction();
if (mLastTab != null) {
if (mLastTab.fragment != null) {
ft.detach(mLastTab.fragment);
}
}
if (newTab != null) {
if (newTab.fragment == null) {
newTab.fragment = Fragment.instantiate(this,
newTab.clss.getName(), newTab.args);
ft.add(R.id.realtabcontent, newTab.fragment, newTab.tag);
} else {
ft.attach(newTab.fragment);
}
}
mLastTab = newTab;
ft.commit();
this.getSupportFragmentManager().executePendingTransactions();
}
}
}
Ce qui est dans la ligne 221 de Tab1Fragment? jetant aussi autour douzaine de lignes de code (pas bien formaté) n'est pas utile ... – WarrenFaith
Salut Warren, Désolé pour la mise en forme pauvre. Je suis dans un désordre en ce moment. Impossible de créer l'application Le contenu de la ligne no.221 est runonUithread (returnRes); Merci – Vyshakh
En éclipse, appuyez sur ctrl + shift + f pour le mettre en forme, puis réexécutez, publiez l'erreur logcat complète et mettez à jour le code. Ensuite, nous pouvons travailler sur la question. Actuellement, votre code est simplement illisible. – WarrenFaith