Android新浪微博客户端（六）——Home界面的ListView

原文出自：方杰|http://fangjie.info/?p=184转载请注明出处

最终效果演示：http://fangjie.info/?page_id=54
该项目代码已经放到github：https://github.com/JayFang1993/SinaWeibo

一.首先是ListView的adapter。

因为微博列表的Item不是规则的，比如说有些微博有转发子微博，有些没有，有些有图片，有些没有图片，所以说很不固定。这里就采用BaseAdapter，要自己为微博Item设计一个WeiboAdapter.java

package com.fangjie.weibo.ui;

import java.util.Date;
import java.util.List;
import com.fangjie.weibo.R;
import com.fangjie.weibo.bean.Weibo;
import android.content.Context;
import android.graphics.Bitmap;
import android.support.v4.util.LruCache;
import android.text.Html;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class WeiboAdapter extends BaseAdapter {

    private Context context;
    private List<Weibo> weibos;    

    public WeiboAdapter(Context context,List<Weibo> weibos) {
        System.out.println(weibos.get(1).content);
        this.context=context;
        this.weibos=weibos;
    }

    public int getCount() {
        return weibos.size();
    }

    public Object getItem(int position) {
        return null;
    }

    public long getItemId(int position) {
        return 0;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
         //position代表位置  

        //通过View关联自定义Item布局，进行填充  

         if(convertView == null)
         {
             convertView = View.inflate(context, R.layout.wb_item, null);
         }

        System.out.println(position);
        final Weibo weibo =weibos.get(position);

        //获取要显示的组件,注意findViewById的调用对象是上面填充了Item的布局的对象View
        TextView tv_name = (TextView)convertView.findViewById(R.id.txt_wb_item_uname);
        TextView tv_content = (TextView)convertView.findViewById(R.id.txt_wb_item_content);
        TextView tv_time =(TextView)convertView.findViewById(R.id.txt_wb_item_time);
        TextView tv_from =(TextView)convertView.findViewById(R.id.txt_wb_item_from);
        TextView tv_comment =(TextView)convertView.findViewById(R.id.txt_wb_item_comment);
        TextView tv_repost =(TextView)convertView.findViewById(R.id.txt_wb_item_redirect);  

        LinearLayout zlayout=(LinearLayout)convertView.findViewById(R.id.lyt_wb_item_sublayout);
        TextView tv_zcontent=(TextView)convertView.findViewById(R.id.txt_wb_item_subcontent); 

        final ImageView iv_userhead=(ImageView)convertView.findViewById(R.id.img_wb_item_head);
        ImageView iv_isv=(ImageView)convertView.findViewById(R.id.img_wb_item_V);
        ImageView iv_content_pic=(ImageView)convertView.findViewById(R.id.img_wb_item_content_pic);
        ImageView iv_zcontent_pic=(ImageView)convertView.findViewById(R.id.img_wb_item_content_subpic);

        //组件添加内容
        tv_content.setText(weibo.getContent());
        tv_name.setText(weibo.getUser().getName());
        tv_from.setText("来自:"+Html.fromHtml(weibo.getFrom()));
        tv_repost.setText(weibo.getReposts_count()+"");
        tv_comment.setText(weibo.getComments_count()+"");
        tv_time.setText(dealTime(weibo.getTime()));

        loadBitmap(weibo.getUser().getProfile_image_url(), iv_userhead,80,80);  

        if(!weibo.getBmiddle_pic().equals(""))
        {
            loadBitmap(weibo.getBmiddle_pic(), iv_content_pic,0,0);
            iv_content_pic.setVisibility(View.VISIBLE);
        }
        else
        {
            iv_content_pic.setVisibility(View.GONE);
        }

        if(weibo.getUser().isIsv())
            iv_isv.setVisibility(View.VISIBLE);
        else
            iv_isv.setVisibility(View.GONE);

        if(weibo.getWeibo()!=null)
        {
            zlayout.setVisibility(View.VISIBLE);
            tv_zcontent.setText("@"+weibo.getWeibo().getUser().getName()+":"+weibo.getWeibo().getContent());
            if(!weibo.getWeibo().getBmiddle_pic().equals(""))
            {
                loadBitmap(weibo.getWeibo().getBmiddle_pic(), iv_zcontent_pic,0,0);
                iv_zcontent_pic.setVisibility(View.VISIBLE);
            }
        }
        else
            zlayout.setVisibility(View.GONE);

        return convertView;
    }

    public void addItem(Weibo weibo)
    {
        weibos.add(weibo);
    }
}

微博Item的布局文件 wb_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:background="@drawable/list_item">
      <ImageView
          android:id="@+id/img_wb_item_head"
          android:layout_width="48dp"
          android:layout_height="48dp"
          android:src="@drawable/user_head"
          android:layout_marginLeft="3dp"
          android:layout_marginTop="5dp"/>

      <!-- 右边框架 -->
      <LinearLayout
      android:layout_width="match_parent"
      android:orientation="vertical"
      android:layout_height="wrap_content"
      android:layout_margin="5dp">
         <!-- 用户名称、新浪认证部分 -->
        <LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:orientation="horizontal">
              <!-- 用户名称 -->
              <TextView android:id="@+id/txt_wb_item_uname"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:textColor="#424d54"
                  android:textSize="15dp"
              />
              <!-- 新浪认证 -->
               <ImageView android:id="@+id/img_wb_item_V"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:visibility="gone"
                      android:src="@drawable/v"/>
              <RelativeLayout
                           android:layout_width="fill_parent"
                        android:layout_height="wrap_content"
                        android:gravity="right">
                      <!-- 发布时间 -->
                     <TextView android:id="@+id/txt_wb_item_time"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:text="1小时前"
                      android:textColor="#efa608"
                      android:textSize="12dp"
                      />
            </RelativeLayout>
         </LinearLayout> 

         <!-- 微博正文内容 -->
        <LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:orientation="vertical">
           <!-- 微博正文内容 -->
             <TextView android:id="@+id/txt_wb_item_content"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:text="微博正文内容微博正文内容微博正文内容微博正文内容微博正文内容微博正文内容微博正文内容"
              android:textColor="#6b717b"
              android:textSize="13dp"
              />
             <ImageView android:id="@+id/img_wb_item_content_pic"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:src="@drawable/user_head"
              android:layout_marginTop="3dp"
              android:visibility="gone"
             />
         </LinearLayout>

           <!-- 转发的子微博内容 -->
        <LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:id="@+id/lyt_wb_item_sublayout"
          android:orientation="vertical"
          android:layout_marginTop="3dp"
          android:visibility="gone"
          android:background="@drawable/popup">

               <!-- 微博正文内容 -->
             <TextView android:id="@+id/txt_wb_item_subcontent"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:text="微博正文内容微博正文内容微博正文内容微博正文内容微博正文内容微博正文内容微博正文内容"
              android:textColor="#6b717b"
              android:textSize="13dp"
              />
             <ImageView android:id="@+id/img_wb_item_content_subpic"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:src="@drawable/user_head"
              android:layout_marginTop="3dp"
              android:visibility="gone"
             />
      </LinearLayout>
           <!-- 微博来源部分 -->
      <LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:orientation="horizontal"
          android:layout_marginTop="3dp"
          android:layout_marginBottom="3dp" >
           <!-- 用户名称 -->
          <TextView android:id="@+id/txt_wb_item_from"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="来自:Touch Android"
              android:textColor="#9ba0aa"
              android:textSize="12dp"
          />
          <LinearLayout
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:orientation="horizontal"
              android:gravity="right">
              <TextView android:id="@+id/txt_wb_item_redirect"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:drawableLeft="@drawable/redirect_icon"
                      android:text="10"
                      android:textColor="#9ba0aa"
                      android:textSize="13dp"
                  />
              <TextView android:id="@+id/txt_wb_item_comment"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:layout_marginLeft="5dp"
                      android:drawableLeft="@drawable/comment_icon"
                      android:text="100"
                      android:textColor="#9ba0aa"
                      android:textSize="13dp"/>
           </LinearLayout>
      </LinearLayout>
  </LinearLayout>
</LinearLayout>

WeiboAdapter的作用就是将List<Weibo> weibos的数据绑定到每一个View的控件上去。注：关于图片ImagView控件的加载loadBitmap采用的是异步加载，在下一篇中会讲到。

二.ListView的细节——底部加载更多

首先需要为这个东西写一个布局文件 load_more.xml，布局很简单，就是一个button。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content">
  <Button
           android:id="@+id/loadMoreButton"
           android:layout_width="fill_parent"
           android:layout_height="wrap_content"
           android:text="加载更多"
           android:onClick="loadMore"/>
</LinearLayout>

然后在HomeActivity.java中为ListView增加一个底部视图，ListView.addFooterView(View view);

        //设置列表底部视图-加载更多
        View loadMoreView = getLayoutInflater().inflate(R.layout.load_more, null);
        loadMoreButton= (Button) loadMoreView.findViewById(R.id.loadMoreButton);
        weibolist.addFooterView(loadMoreView);

三.ListView的刷新按钮

在点击主界面的刷新按钮时，会出现progressbar，这些都不是很难。首先写好一个progress的布局，在刷新任务开始之前然progressbar显示，任务结束后就View.gone就OK啦，详细请看源代码HomeActivity.

四.注意：我在写ListView的时候，在模拟器测试完全OK，但是在真机上调试时，ListView与上面的TitleBar和TabHost交界处会有阴影。加上这句就可以了。

ListView.setFadingEdgeLength(0);

可能讲的不是很直观，最后附上HomeActivity.java的全部代码，这个就是Home界面的代码

package com.fangjie.weibo.ui;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.fangjie.weibo.R;
import com.fangjie.weibo.bean.Task;
import com.fangjie.weibo.bean.Weibo;
import com.fangjie.weibo.logic.MainService;
import com.fangjie.weibo.util.SharePreferencesUtil;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class HomeActivity extends Activity implements IWeiboAcitivity {
    private ListView weibolist;
    private List<Weibo> weibos;
    private WeiboAdapter adapter;

    private TextView tv_title;
    private Button btn_refresh;
    private Button btn_update;

    private LinearLayout progress;

    private Button loadMoreButton;

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.home);
        init();
    }

    public void init() {
        weibolist=(ListView)findViewById(R.id.lv_weibos);
        tv_title=(TextView)findViewById(R.id.txt_wb_title);
        btn_refresh=(Button)findViewById(R.id.btn_refresh);
        btn_update=(Button)findViewById(R.id.btn_writer);
        progress=(LinearLayout)findViewById(R.id.layout_progress);

        //设置列表底部视图-加载更多
        View loadMoreView = getLayoutInflater().inflate(R.layout.load_more, null);
        loadMoreButton= (Button) loadMoreView.findViewById(R.id.loadMoreButton);
        weibolist.addFooterView(loadMoreView);   

        weibolist.setFadingEdgeLength(0);

        final String token=SharePreferencesUtil.getLoginUser(HomeActivity.this).getToken();
        tv_title.setText(SharePreferencesUtil.getLoginUser(HomeActivity.this).getUserName());

        Map<String,Object> params=new HashMap<String,Object>();
        params.put("token", token);
        Task task=new Task(Task.GET_WEIBOS, params);
        progress.setVisibility(View.VISIBLE);
        MainService.newTask(task);
        MainService.addActivty(HomeActivity.this);

        loadMoreButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                Map<String,Object> params=new HashMap<String,Object>();
                params.put("token", token);
                params.put("max_id", weibos.get(weibos.size()-1).getWid());
                loadMoreButton.setText("正在加载，请稍候...");
                Task task=new Task(Task.LOADMORE, params);
                MainService.newTask(task);
                MainService.addActivty(HomeActivity.this);
            }
        });

        btn_refresh.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                Map<String,Object> params=new HashMap<String,Object>();
                params.put("token", token);
                progress.setVisibility(View.VISIBLE);
                Task task=new Task(Task.GET_WEIBOS, params);
                MainService.newTask(task);
                MainService.addActivty(HomeActivity.this);
            }
        });

        btn_update.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                Toast.makeText(HomeActivity.this, "亲，程序猿还没写好呢...", Toast.LENGTH_LONG).show();
            }
        });
    }

    @SuppressWarnings("unchecked")
    public void refresh(int taskID, Object... objects) {
        switch (taskID)
        {
            case Task.GET_WEIBOS:
                weibos=(List<Weibo>)objects[0];
                adapter=new WeiboAdapter(HomeActivity.this,weibos);
                weibolist.setAdapter(adapter);
                break;
            case Task.LOADMORE:
                weibos=(List<Weibo>)objects[0];
                for(int i=1;i<weibos.size();i++)
                    adapter.addItem(weibos.get(i));
                adapter.notifyDataSetChanged(); //数据集变化后,通知adapter
                loadMoreButton.setText("加载更多");
        }
        progress.setVisibility(View.GONE);
        MainService.reMoveActivty(HomeActivity.this);
    }
}

可能大家在HomeActivity中只看到新开一些任务，但是这些任务具体做什么操纵不清楚，大家可以看看前面的博文，因为有一个 逻辑处理的MainService处理类。针对Task.GET_WEIBOS和Task.LOADMORE，其中的代码又增加了。这里也附上MainService.java关于这两个任务的部分代码。

            //刷新微博
            case Task.GET_WEIBOS:
            {
                String token=(String)task.getParams().get("token");
                WeiboUtil weiboutil=new WeiboUtil();
                List<Weibo> weibos=weiboutil.getWeiboList(token,0);
                msg.obj=weibos;
                break;
            }
            //加载更多
            case Task.LOADMORE:
            {
                String token=(String)task.getParams().get("token");
                long max_id=(Long) task.getParams().get("max_id");
                WeiboUtil weiboutil=new WeiboUtil();
                List<Weibo> weibos=weiboutil.getWeiboList(token,max_id);
                msg.obj=weibos;
                break;
            }