android开发我的新浪微博客户端-用户首页面功能篇(5.2)

 

上一篇完成用户首页的UI实现，本篇接下来讲功能部分的实现，本页面主要的功能就用户关注的最新微博列表，从上一篇中知道本列表是用ID为Msglist的ListView控件来实现，本篇的主要就讲解如果获取微博列表数据给这个ListView提供显示数据。ListView每一条子数据分别由用户头像、用户昵称、发布时间、是否包含照片、微博内容这五部分组成，根据这五部分定义一个名为WeiBoInfo.java实体类，代码如下：

代码 public class WeiBoInfo { // 文章id private String id; public String getId(){ return id;} public void setId(String id){ this .id = id;} // 发布人id private String userId; public String getUserId(){ return userId;} public void setUserId(String userId){ this .userId = userId;} // 发布人名字 private String userName; public String getUserName(){ return userName;} public void setUserName(String userName){ this .userName = userName;} // 发布人头像 private String userIcon; public String getUserIcon(){ return userIcon;} public void setUserIcon(String userIcon){ this .userIcon = userIcon;} // 发布时间 private String time; public String getTime(){ return time;} public void setTime(String time){ this .time = time;} // 是否有图片 private Boolean haveImage = false ; public Boolean getHaveImage(){ return haveImage;} public void setHaveImage(Boolean haveImage){ this .haveImage = haveImage;} // 文章内容 private String text; public String getText(){ return text;} public void setText(String text){ this .text = text;}}

然后在res/layout目录下新建名为weibo.xml的Layout用来控制ListView子项的显示部件，代码很简单不多解释了，直接看下面代码：

代码 <? xml version="1.0" encoding="utf-8" ?> < LinearLayout xmlns:android ="http://schemas.android.com/apk/res/android" android:layout_width ="wrap_content" android:layout_height ="wrap_content" android:orientation ="horizontal" > < ImageView android:id ="@+id/wbicon" android:layout_width ="wrap_content" android:layout_height ="wrap_content" android:src ="@drawable/usericon" android:layout_margin ="8px" > </ ImageView > < LinearLayout android:layout_width ="fill_parent" android:layout_height ="wrap_content" android:orientation ="vertical" android:paddingLeft ="0px" android:paddingRight ="5px" android:layout_marginTop ="5px" android:layout_marginBottom ="5px" > < RelativeLayout android:layout_width ="fill_parent" android:layout_height ="wrap_content" > < TextView android:id ="@+id/wbuser" android:layout_width ="wrap_content" android:layout_height ="wrap_content" android:textSize ="15px" android:textColor ="#424952" android:layout_alignParentLeft ="true" > </ TextView > < ImageView android:id ="@+id/wbimage" android:layout_width ="wrap_content" android:layout_height ="wrap_content" android:layout_marginTop ="3px" android:layout_marginRight ="5px" android:layout_toLeftOf ="@+id/wbtime" > </ ImageView > < TextView android:id ="@+id/wbtime" android:layout_width ="wrap_content" android:layout_height ="wrap_content" android:layout_alignParentRight ="true" android:textColor ="#f7a200" android:textSize ="12px" > </ TextView > </ RelativeLayout > < TextView android:id ="@+id/wbtext" android:layout_width ="wrap_content" android:layout_height ="wrap_content" android:textColor ="#424952" android:textSize ="13px" android:layout_marginTop ="4px" > </ TextView > </ LinearLayout > </ LinearLayout >

接下来为列表控件定义一个数据Adapter，代码如下：

代码 private List < WeiBoInfo > wbList; // 微博列表Adapater public class WeiBoAdapater extends BaseAdapter{ private AsyncImageLoader asyncImageLoader;@Override public int getCount() { return wbList.size();}@Override public Object getItem( int position) { return wbList.get(position);}@Override public long getItemId( int position) { return position;}@Override public View getView( int position, View convertView, ViewGroup parent) {asyncImageLoader = new AsyncImageLoader();convertView = LayoutInflater.from(getApplicationContext()).inflate(R.layout.weibo, null );WeiBoHolder wh = new WeiBoHolder();wh.wbicon = (ImageView) convertView.findViewById(R.id.wbicon);wh.wbtext = (TextView) convertView.findViewById(R.id.wbtext);wh.wbtime = (TextView) convertView.findViewById(R.id.wbtime);wh.wbuser = (TextView) convertView.findViewById(R.id.wbuser);wh.wbimage = (ImageView) convertView.findViewById(R.id.wbimage);WeiBoInfo wb = wbList.get(position); if (wb != null ){convertView.setTag(wb.getId());wh.wbuser.setText(wb.getUserName());wh.wbtime.setText(wb.getTime());wh.wbtext.setText(wb.getText(), TextView.BufferType.SPANNABLE);textHighlight(wh.wbtext, new char []{ ' # ' }, new char []{ ' # ' });textHighlight(wh.wbtext, new char []{ ' @ ' }, new char []{ ' : ' , ' ' });textHighlight2(wh.wbtext, " http:// " , " " ); if (wb.getHaveImage()){wh.wbimage.setImageResource(R.drawable.images);}Drawable cachedImage = asyncImageLoader.loadDrawable(wb.getUserIcon(),wh.wbicon, new ImageCallback(){@Override public void imageLoaded(Drawable imageDrawable,ImageView imageView, String imageUrl) {imageView.setImageDrawable(imageDrawable);}}); if (cachedImage == null ) {wh.wbicon.setImageResource(R.drawable.usericon);} else {wh.wbicon.setImageDrawable(cachedImage);}} return convertView;}

上面的这个Adapter实现没有什么特别的很普通，不过这个中使用了AsyncImageLoader的方法，这个是用来实现用户头像图标的异步载入显示，这样能提高列表显示的速度，提高用户体验，AsyncImageLoader的代码如下：

代码 public class AsyncImageLoader { // SoftReference是软引用，是为了更好的为了系统回收变量 private HashMap < String, SoftReference < Drawable >> imageCache; public AsyncImageLoader() {imageCache = new HashMap < String, SoftReference < Drawable >> ();} public Drawable loadDrawable( final String imageUrl, final ImageView imageView, final ImageCallback imageCallback){ if (imageCache.containsKey(imageUrl)) { // 从缓存中获取 SoftReference < Drawable > softReference = imageCache.get(imageUrl);Drawable drawable = softReference.get(); if (drawable != null ) { return drawable;}} final Handler handler = new Handler() { public void handleMessage(Message message) {imageCallback.imageLoaded((Drawable) message.obj, imageView,imageUrl);}}; // 建立新一个新的线程下载图片 new Thread() {@Override public void run() {Drawable drawable = loadImageFromUrl(imageUrl);imageCache.put(imageUrl, new SoftReference < Drawable > (drawable));Message message = handler.obtainMessage( 0 , drawable);handler.sendMessage(message);}}.start(); return null ;} public static Drawable loadImageFromUrl(String url){URL m;InputStream i = null ; try {m = new URL(url);i = (InputStream) m.getContent();} catch (MalformedURLException e1) {e1.printStackTrace();} catch (IOException e) {e.printStackTrace();}Drawable d = Drawable.createFromStream(i, " src " ); return d;} // 回调接口 public interface ImageCallback { public void imageLoaded(Drawable imageDrawable,ImageView imageView, String imageUrl);}}

 

完成上述的工作后，接下来就是显示微薄列表， 在HomeActivity的onCreate方法中调用loadList();代码如下：

代码 @Override public void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState);setContentView(R.layout.home);。。。。。。loadList();} private void loadList(){ if (ConfigHelper.nowUser == null ){} else {user = ConfigHelper.nowUser; // 显示当前用户名称 TextView showName = (TextView)findViewById(R.id.showName);showName.setText(user.getUserName());OAuth auth = new OAuth();String url = " http://api.t.sina.com.cn/statuses/friends_timeline.json " ;List params = new ArrayList();params.add( new BasicNameValuePair( " source " , auth.consumerKey)); HttpResponse response = auth.SignRequest(user.getToken(), user.getTokenSecret(), url, params); if ( 200 == response.getStatusLine().getStatusCode()){ try {InputStream is = response.getEntity().getContent();Reader reader = new BufferedReader( new InputStreamReader(is), 4000 );StringBuilder buffer = new StringBuilder(( int ) response.getEntity().getContentLength()); try { char [] tmp = new char [ 1024 ]; int l; while ((l = reader.read(tmp)) != - 1 ) {buffer.append(tmp, 0 , l);}} finally {reader.close();}String string = buffer.toString(); // Log.e("json", "rs:" + string); response.getEntity().consumeContent();JSONArray data = new JSONArray(string); for ( int i = 0 ;i < data.length();i ++ ){JSONObject d = data.getJSONObject(i); // Log.e("json", "rs:" + d.getString("created_at")); if (d != null ){JSONObject u = d.getJSONObject( " user " ); if (d.has( " retweeted_status " )){JSONObject r = d.getJSONObject( " retweeted_status " );} // 微博id String id = d.getString( " id " );String userId = u.getString( " id " );String userName = u.getString( " screen_name " );String userIcon = u.getString( " profile_image_url " );Log.e( " userIcon " , userIcon);String time = d.getString( " created_at " );String text = d.getString( " text " );Boolean haveImg = false ; if (d.has( " thumbnail_pic " )){haveImg = true ; // String thumbnail_pic=d.getString("thumbnail_pic"); // Log.e("thumbnail_pic", thumbnail_pic); }Date date = new Date(time);time = ConvertTime(date); if (wbList == null ){wbList = new ArrayList < WeiBoInfo > ();}WeiBoInfo w = new WeiBoInfo();w.setId(id);w.setUserId(userId);w.setUserName(userName);w.setTime(time);w.setText(text);w.setHaveImage(haveImg);w.setUserIcon(userIcon);wbList.add(w);}}} catch (IllegalStateException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();} catch (JSONException e) {e.printStackTrace();} } if (wbList != null ){WeiBoAdapater adapater = new WeiBoAdapater();ListView Msglist = (ListView)findViewById(R.id.Msglist);Msglist.setOnItemClickListener( new OnItemClickListener(){@Override public void onItemClick(AdapterView <?> arg0, View view, int arg2, long arg3) {Object obj = view.getTag(); if (obj != null ){String id = obj.toString();Intent intent = new Intent(HomeActivity. this ,ViewActivity. class );Bundle b = new Bundle();b.putString( " key " , id);intent.putExtras(b);startActivity(intent);}}});Msglist.setAdapter(adapater);}}loadingLayout.setVisibility(View.GONE);}

 

上面的loadList() 方法通过新浪Api接口http://api.t.sina.com.cn/statuses/friends_timeline.json获取当前登录用户及其所关注用户的最新微博消息，然后显示到列表中。

这样就完成了用户首页功能的开发。