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：

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：

<?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：

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：

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：

@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。