我目前正在创建一个RSS阅读应用程序，它使用页面查看器....这样用户就可以在应用程序中的不同视图/提要之间滑动。
问题是，一旦我刷到第二个视图，应用程序就会冻结......因为它试图同时加载太多数据。
所以我想问一下，加载前一个视图后是否有添加每个视图的方法;或任何真正使应用程序加载数据而不冻结的东西，并使其加载更顺畅。
任何帮助都会很棒！感谢。
此代码是我添加视图的方式：
package com.example.directrssread;
import java.util.List;
import java.util.Vector;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
public class ViewPagerFragmentActivity extends FragmentActivity{
/** maintains the pager adapter*/
private PagerAdapter mPagerAdapter;
/* (non-Javadoc)
* @see android.support.v4.app.FragmentActivity#onCreate(android.os.Bundle)
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setContentView(R.layout.viewpager);
//initialsie the pager
this.initialisePaging();
}
/**
* Initialise the fragments to be paged
*/
private void initialisePaging() {
List<Fragment> fragments = new Vector<Fragment>();
fragments.add(Fragment.instantiate(this, Feed1.class.getName()));
fragments.add(Fragment.instantiate(this, Feed2.class.getName()));
fragments.add(Fragment.instantiate(this, Feed3.class.getName()));
//fragments.add(Fragment.instantiate(this, Feed4.class.getName()));
// fragments.add(Fragment.instantiate(this, Tab3Fragment.class.getName()));
this.mPagerAdapter = new PagerAdapter1(super.getSupportFragmentManager(), fragments);
//
ViewPager pager = (ViewPager)super.findViewById(R.id.viewpager);
pager.setAdapter(this.mPagerAdapter);
}
}
This code is from one of my views (they all have the same code, and there are 4 of them)
package com.example.directrssread;
import java.util.ArrayList;
import java.util.HashMap;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import android.content.Intent;
import android.os.Bundle;
import android.os.StrictMode;
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.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class Feed1 extends ListFragment{
String[] URL = new String[3];
int count = 0;
String currURL = "";
ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();
// XML node keys
static final String KEY_ITEM = "item"; // parent node
static final String KEY_ID = "id";
static final String KEY_NAME = "name";
static final String KEY_TITLE = "title";
static final String KEY_COST = "cost";
static final String KEY_DESC = "description";
static final String KEY_LINK = "link";
static final String KEY_PUBDATE = "pubDate";
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
return inflater.inflate(R.layout.feed1, container, false);
}
public void onActivityCreated(Bundle savedInstanceState) {
// rssRun();
boolean runSubstring = true;
//URL[0] = "http://newsrss.bbc.co.uk/rss/sportonline_uk_edition/football/teams/a/arsenal/rss.xml";
URL[0] = "http://talksport.com/rss/football/premier-league/feed";
URL[1] = "http://feeds.bbci.co.uk/sport/0/football/rss.xml?edition=uk";
URL[2] = "http://talksport.com/rss/football/premier-league/feed";
//URL[3] = "http://feeds.bbci.co.uk/sport/0/football/rss.xml?edition=uk";
for (int f= 0;f < URL.length;f++)
{
try{
//Log.e("TEst1", "TEst");
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL[f]); // getting XML
Document doc = parser.getDomElement(xml); // getting DOM element
//Log.e("XML", xml);
NodeList nl = doc.getElementsByTagName(KEY_ITEM);
//Log.e("NODELIST", nl.toString());
// looping through all item nodes <item>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
if (doc!=null)
{
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
if (count == 0)
{
currURL = "Football365";
}
if (count == 1)
{
currURL = "BBC Sport";
}
if (count == 2)
{
currURL = "TalkSport";
}
map.put(KEY_ID, parser.getValue(e, KEY_ID));
//Get the title of the article.
map.put(KEY_NAME, parser.getValue(e, KEY_TITLE));
//Get the description of the article.
map.put(KEY_DESC, parser.getValue(e, KEY_DESC));
//Get the source e.g ' Football365'.
//String pubDate = parser.getValue(e, KEY_PUBDATE);
String pubDate = parser.getValue(e, KEY_PUBDATE);
//Parse the date and time from the main strings.
//Chop off the un-wanted parts.
//Bring them back together in one string.
String pubTime = pubDate.substring(17, pubDate.length());
pubTime = pubTime.substring(0, 5);
pubDate = pubDate.substring(0, 16);
pubDate = pubDate + " " + pubTime;
//Log.e("TITLE", )
map.put(KEY_TITLE, currURL + " - " + pubDate);
//Add the link.
map.put(KEY_LINK, parser.getValue(e, KEY_LINK));
//Get the publish date.
//map.put(KEY_PUBDATE, parser.getValue(e, KEY_PUBDATE));
// adding HashList to ArrayList
menuItems.add(map);
Log.e("TEst", "TEst");
for (int q = 0;q < map.size();q++)
{
Log.e("mene", map.get(KEY_TITLE));
}
}
}
count+=1;
}
catch(Exception e)
{
Log.e("ERROR", e.toString());
}
// Adding menuItems to ListView
ListAdapter adapter = new SimpleAdapter(getActivity(), menuItems,
R.layout.list_item,
new String[] { KEY_NAME, KEY_DESC,KEY_LINK, KEY_TITLE }, new int[] {
R.id.name, R.id.desciption, R.id.link, R.id.source});
//if (count==3)
//{
setListAdapter(adapter);
//}
// selecting single ListView item
ListView lv = getListView();
//TextView firstName = (TextView) V.findViewById(R.id.textView1);
//EditText firstName = (EditText) findViewById(R.id.display_name);
//ListView lv = (ListView) findViewById(R.id.l)
//ListView lv = ((ListView) findViewbyId(R.id)
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String cost = ((TextView) view.findViewById(R.id.cost)).getText().toString();
String link = ((TextView) view.findViewById(R.id.link)).getText().toString();
String description = ((TextView) view.findViewById(R.id.desciption)).getText().toString();
// Starting new intent
Intent in = new Intent(getActivity().getApplication(), SingleMenuItemActivity.class);
in.putExtra(KEY_NAME, name);
in.putExtra(KEY_COST, cost);
in.putExtra(KEY_DESC, description);
in.putExtra(KEY_LINK, link);
startActivity(in);
}
});
}
Log.e("RUN", "RSSRUN");
super.onActivityCreated(savedInstanceState);
}
public void rssRun()
{
boolean runSubstring = true;
//URL[0] = "http://newsrss.bbc.co.uk/rss/sportonline_uk_edition/football/teams/a/arsenal/rss.xml";
URL[0] = "http://talksport.com/rss/football/premier-league/feed";
URL[1] = "http://feeds.bbci.co.uk/sport/0/football/rss.xml?edition=uk";
URL[2] = "http://talksport.com/rss/football/premier-league/feed";
//URL[3] = "http://feeds.bbci.co.uk/sport/0/football/rss.xml?edition=uk";
for (int f= 0;f < URL.length;f++)
{
try{
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL[f]); // getting XML
Document doc = parser.getDomElement(xml); // getting DOM element
//Log.e("XML", xml);
NodeList nl = doc.getElementsByTagName(KEY_ITEM);
//Log.e("NODELIST", nl.toString());
// looping through all item nodes <item>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
if (doc!=null)
{
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
if (count == 0)
{
currURL = "Football365";
}
if (count == 1)
{
currURL = "BBC Sport";
}
if (count == 2)
{
currURL = "TalkSport";
}
map.put(KEY_ID, parser.getValue(e, KEY_ID));
//Get the title of the article.
map.put(KEY_NAME, parser.getValue(e, KEY_TITLE));
//Get the description of the article.
map.put(KEY_DESC, parser.getValue(e, KEY_DESC));
//Get the source e.g ' Football365'.
//String pubDate = parser.getValue(e, KEY_PUBDATE);
String pubDate = parser.getValue(e, KEY_PUBDATE);
//Parse the date and time from the main strings.
//Chop off the un-wanted parts.
//Bring them back together in one string.
String pubTime = pubDate.substring(17, pubDate.length());
pubTime = pubTime.substring(0, 5);
pubDate = pubDate.substring(0, 16);
pubDate = pubDate + " " + pubTime;
//Log.e("TITLE", )
map.put(KEY_TITLE, currURL + " - " + pubDate);
//Add the link.
map.put(KEY_LINK, parser.getValue(e, KEY_LINK));
//Get the publish date.
//map.put(KEY_PUBDATE, parser.getValue(e, KEY_PUBDATE));
// adding HashList to ArrayList
menuItems.add(map);
for (int q = 0;q < map.size();q++)
{
Log.e("mene", map.get(KEY_TITLE));
}
}
}
count+=1;
}
catch(Exception e)
{
}
// Adding menuItems to ListView
final ListAdapter adapter = new SimpleAdapter(getActivity(), menuItems,
R.layout.list_item,
new String[] { KEY_NAME, KEY_DESC,KEY_LINK, KEY_TITLE }, new int[] {
R.id.name, R.id.desciption, R.id.link, R.id.source});
//if (count==3)
//{
new Thread(new Runnable() {
public void run() {
new Thread(new Runnable() {
public void run() {
setListAdapter(adapter);
}
});
}
}).start();
//setListAdapter(adapter);
//}
// selecting single ListView item
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String cost = ((TextView) view.findViewById(R.id.cost)).getText().toString();
String link = ((TextView) view.findViewById(R.id.link)).getText().toString();
String description = ((TextView) view.findViewById(R.id.desciption)).getText().toString();
// Starting new intent
Intent in = new Intent(getActivity().getApplication(), SingleMenuItemActivity.class);
in.putExtra(KEY_NAME, name);
in.putExtra(KEY_COST, cost);
in.putExtra(KEY_DESC, description);
in.putExtra(KEY_LINK, link);
startActivity(in);
}
});
}
}
/*protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.feed1);
////initialsie the pager
//this.initialisePaging();
}*/
}
答案 0 :(得分：0)
在活动生命周期方法中执行耗时的任务并不是一种好习惯。相反，你应该使用加载器和你的碎片。加载程序可以在后台加载数据，同时您可以显示进度对话框。在加载程序中完成加载后，您可以在片段中显示数据。 这将使UI响应。 从这里了解更多关于装载机的信息
http://developer.android.com/guide/components/loaders.html http://developer.android.com/reference/android/content/Loader.html