<activity
android:name=".RSSMainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
2. RSSMainActivity:
1） 用ListView显示RSS Reader获取的数据结果
定义ListView的list layout 和 item layout
activity_postlist.xml
<?xml version="1.0" encoding="utf-8"?>
<!-- activity_postlist.xml -->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".RSSMainActivity" >
<ListView
android:id="@+id/postListView"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</RelativeLayout>
postitem.xml: 显示RSS的title和pubDate
<?xml version="1.0" encoding="utf-8"?>
<!-- postitem.xml -->
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:paddingTop="5dp"
android:paddingBottom="5dp"
>
<ImageView
android:id="@+id/postThumb"
android:layout_width="60dp"
android:layout_height="60dp"
android:src="@drawable/ic_launcher"
android:scaleType="centerCrop"
android:layout_marginRight="5dp"/>
<TextView
android:id="@+id/postTitleLabel"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignTop="@id/postThumb"
android:layout_toRightOf="@id/postThumb"
android:maxLines="2"
android:text="This is a good Post, I hope it will have 2 lines. Please give me 2 lines"
android:textIsSelectable="false"
android:textSize="14sp"
android:ellipsize="end"/>
<TextView
android:id="@+id/postDateLabel"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignBottom="@id/postThumb"
android:layout_toRightOf="@id/postThumb"
android:maxLines="1"
android:text="April 12, 2013"
android:textSize="10sp"
/>
</RelativeLayout>
RSSMainActivity.java中，添加listview。
public class RSSMainActivity extends Activity {
private ArrayList<PostData> listData = new ArrayList<PostData>();
private PostItemAdapter itemAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_postlist);
ListView listView = (ListView) this.findViewById(R.id.postListView);
itemAdapter = new PostItemAdapter(this,R.layout.postitem, listData);
listView.setAdapter(itemAdapter);
}
}
定义RSSFeed的Model
public class PostData {
public String postThumbUrl;
public String postTitle;
public String postDate;
}
2） 自定义Adapter， 实现listView.setAdapter的方法
public class PostItemAdapter extends ArrayAdapter<PostData> {
private Activity myContext;
private ArrayList<PostData> datas;
static class ViewHolder{
TextView postTitleView;
TextView postDateView;
ImageView postThumbView;
}
public PostItemAdapter(Context context, int textViewResourceId, ArrayList<PostData> objects){
super(context, textViewResourceId, objects);
myContext = (Activity) context;
datas = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if(convertView==null){
LayoutInflater inflater = myContext.getLayoutInflater();
convertView = inflater.inflate(R.layout.postitem, null);
viewHolder = new ViewHolder();
viewHolder.postThumbView = (ImageView) convertView.findViewById(R.id.postThumb);
viewHolder.postTitleView = (TextView) convertView.findViewById(R.id.postTitleLabel);
viewHolder.postDateView = (TextView) convertView.findViewById(R.id.postDateLabel);
convertView.setTag(viewHolder);
}else{
viewHolder = (ViewHolder) convertView.getTag();
}
if(datas.get(position).postThumbUrl == null){
viewHolder.postThumbView.setImageResource(R.drawable.ic_launcher);
}
viewHolder.postTitleView.setText(datas.get(position).postTitle);
viewHolder.postDateView.setText(datas.get(position).postDate);
return convertView;
}
}
3） 使用AsyncTask从后台获取数据
在RSSMainActivity中定义AsyncTask， 使用HttpURLConnection获取数据，并解析显示在 list中
private enum RSSXMLTag{
TITLE, DATE, LINK, CONTENT, GUID, IGNORETAG;
}
private class RSSDataController extends AsyncTask<String, Integer, ArrayList<PostData>>{
private RSSXMLTag currentTag;
@Override
protected void onPostExecute(ArrayList<PostData> result) {
for(int i=0;i<result.size();i++){
listData.add(result.get(i));
}
itemAdapter.notifyDataSetChanged();
}
@Override
protected ArrayList<PostData> doInBackground(String... params) {
String urlStr = params[0];
InputStream is = null;
ArrayList<PostData> postDataList = new ArrayList<PostData>();
try{
URL url = new URL(urlStr);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setReadTimeout(10*1000);
connection.setConnectTimeout(10*1000);
connection.setRequestMethod("GET");
connection.setDoInput(true);
connection.connect();
int response = connection.getResponseCode();
Log.d("debug", "the response is:" + response);
is = connection.getInputStream();
XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
factory.setNamespaceAware(true);
XmlPullParser xpp = factory.newPullParser();
xpp.setInput(is,null);
int eventType = xpp.getEventType();
PostData pdData = null;
SimpleDateFormat dateFormat = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz", Locale.ENGLISH);
while (eventType!=XmlPullParser.END_DOCUMENT){
if(eventType == XmlPullParser.START_DOCUMENT){
}else if(eventType == XmlPullParser.START_TAG){
if(xpp.getName().equals("item")){
pdData = new PostData();
currentTag = RSSXMLTag.IGNORETAG;
}else if(xpp.getName().equals("title")){
currentTag = RSSXMLTag.TITLE;
}else if(xpp.getName().equals("link")){
currentTag = RSSXMLTag.LINK;
}else if(xpp.getName().equals("pubDate")){
currentTag = RSSXMLTag.DATE;
}
}else if(eventType == XmlPullParser.END_TAG){
if(xpp.getName().equals("item")){
Date postDate = dateFormat.parse(pdData.postDate);
pdData.postDate = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")).format(postDate);
postDataList.add(pdData);
}else{
currentTag = RSSXMLTag.IGNORETAG;
}
}else if(eventType == XmlPullParser.TEXT){
String content = xpp.getText();
content = content.trim();
Log.d("debug", content);
if(pdData!=null){
switch (currentTag){
case TITLE:
if(content.length()!=0){
if(pdData.postTitle !=null){
pdData.postTitle += content;
}else{
pdData.postTitle = content;
}
}
break;
case LINK:
if(content.length()!=0){
if(pdData.postThumbUrl!=null){
pdData.postThumbUrl += content;
}else{
pdData.postThumbUrl = content;
}
}
break;
case DATE:
if(content.length()!=0){
if(pdData.postDate !=null){
pdData.postDate += content;
}else{
pdData.postDate = content;
}
}
break;
default:
break;
}
}
}
eventType = xpp.next();
}
}catch(MalformedURLException e){
Log.e("malformedURL error", e.getLocalizedMessage());
}catch(IOException e){
Log.e("IO error", e.getLocalizedMessage());
}catch(XmlPullParserException e){
Log.e("XmlPullParser error", e.getLocalizedMessage());
}
catch (ParseException e) {
Log.e("Parse error", e.getLocalizedMessage());
}
return postDataList;
}
}
在RSSMainActivity中启用onStart方法，在该方法中运行后台AsyncTask的服务
@Override
protected void onStart() {
super.onStart();
RSSDataController task = new RSSDataController();
String rssUrl = "http://10.4.251.146/igrp/rssfeed.rss";
String[] params = new String[]{rssUrl};
task.execute(params);
}