(转摘)Android腾讯微博客户端开发五:利用FootView实现ListView滑动动态加载实现分页

(转摘)Android腾讯微博客户端开发5:利用FootView实现ListView滑动动态加载实现分页


看布局代码：布局代码还用到了include，主要是用来重用布局的。
?

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent"><LinearLayout android:orientation="vertical" android:background="#ffffffff" android:layout_width="fill_parent" android:layout_height="fill_parent"><ListView android:id="@id/android:list" android:paddingTop="45.0dip" android:paddingBottom="50.0dip" android:layout_width="fill_parent" android:cacheColorHint="#00000000" android:fadingEdge="none" android:fastScrollEnabled="false" android:clipToPadding="false"android:layout_height="wrap_content" android:divider="@drawable/list_divider"/><TextView android:text="" android:textSize="20.0sp" android:textColor="#ff5a5a5a" android:gravity="center_horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:paddingTop="15.0dip" android:visibility="invisible"/></LinearLayout><include android:id="@+id/home_top" layout="@layout/top_panel" android:layout_width="fill_parent" android:layout_height="wrap_content" /></FrameLayout>
把图片往下拉，此时还未到加载到数据的最底部。

继续往下拉，ok，见底了，看到更多的提示了嘛，点击他


出现进度条提示

加载完毕之后显示新的一页，继续往下拉，又会看见更多提示，然后如此循环。主要是利用了隐藏。


下面看看主的Activity的代码：

?
public class HomeTimeLineActivity extends ListActivity implements OnItemClickListener,OnItemLongClickListener{private DataHelper dataHelper;private UserInfo user;private MyWeiboSync weibo;private ListView listView;private HomeAdapter adapter;private JSONArray array;private AsyncImageLoader asyncImageLoader;private Handler handler;private ProgressDialog progressDialog;private View top_panel;private Button top_btn_left;private Button top_btn_right;private TextView top_title;private LinearLayout list_footer;private TextView tv_msg;private LinearLayout loading;private List<JSONObject> list;//微博数据列表private ExecutorService executorService;private static int PAGE_SIZE = 5;//每页显示的微博条数private int TOTAL_PAGE = 0;//当前已经记在的微博页数private static int THREADPOOL_SIZE = 5;//线程池的大小@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.home);setUpViews();setUpListeners();dataHelper = DataBaseContext.getInstance(getApplicationContext());weibo = WeiboContext.getInstance();List<UserInfo> userList = dataHelper.GetUserList(false);SharedPreferences preferences = getSharedPreferences("default_user",Activity.MODE_PRIVATE);String nick = preferences.getString("user_default_nick", "");//取得默认账号信息if (nick != "") {user = dataHelper.getUserByName(nick,userList);top_title.setText(nick);//顶部工具栏昵称}weibo.setAccessTokenKey(user.getToken());weibo.setAccessTokenSecrect(user.getTokenSecret());progressDialog = new ProgressDialog(HomeTimeLineActivity.this);// 生成一个进度条progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);progressDialog.setTitle("请稍等");progressDialog.setMessage("正在读取数据中!");handler = new GetHomeTimeLineHandler();executorService.submit(new GetHomeTimeLineThread());//耗时操作,开启一个新线程获取数据progressDialog.show();}private void setUpViews(){list_footer = (LinearLayout)LayoutInflater.from(HomeTimeLineActivity.this).inflate(R.layout.list_footer, null);tv_msg = (TextView)list_footer.findViewById(R.id.tv_msg);loading = (LinearLayout)list_footer.findViewById(R.id.loading);listView = getListView();top_panel = (View)findViewById(R.id.home_top);top_btn_left = (Button)top_panel.findViewById(R.id.top_btn_left);top_btn_right = (Button)top_panel.findViewById(R.id.top_btn_right);top_title = (TextView)top_panel.findViewById(R.id.top_title);listView.addFooterView(list_footer);//这儿是关键中的关键呀，利用FooterVIew分页动态加载list = new ArrayList<JSONObject>();executorService = Executors.newFixedThreadPool(THREADPOOL_SIZE);}private void setUpListeners(){listView.setOnItemClickListener(this);listView.setOnItemLongClickListener(this);top_btn_right.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {Intent intent = new Intent(HomeTimeLineActivity.this,AddWeiboActivity.class);startActivity(intent);}});tv_msg.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {//Toast.makeText(HomeTimeLineActivity.this, "我将消失了", Toast.LENGTH_SHORT).show();executorService.submit(new GetHomeTimeLineThread());tv_msg.setVisibility(View.GONE);//隐藏更多提示的TextViewloading.setVisibility(View.VISIBLE);//显示最下方的进度条}});}class GetHomeTimeLineHandler extends Handler {@Overridepublic void handleMessage(Message msg) {adapter = new HomeAdapter(HomeTimeLineActivity.this, list);listView.setAdapter(adapter);listView.setSelection((TOTAL_PAGE-1)*PAGE_SIZE+1);//设置最新获取一页数据成功后显示数据的起始数据progressDialog.dismiss();// 关闭进度条loading.setVisibility(View.GONE);//隐藏下方的进度条tv_msg.setVisibility(View.VISIBLE);//显示出更多提示TextView}}class GetHomeTimeLineThread extends Thread {@Overridepublic void run() {refreshList();Message msg = handler.obtainMessage();//通知线程来处理范围的数据handler.sendMessage(msg);}}private void refreshList(){String jsonStr = weibo.getHomeMsg(weibo.getAccessTokenKey(), weibo.getAccessTokenSecrect(), PageFlag.PageFlag_First, (TOTAL_PAGE+1)*PAGE_SIZE);try {JSONObject dataObj = new JSONObject(jsonStr).getJSONObject("data");array = dataObj.getJSONArray("info");if(array!=null&&array.length()>0){TOTAL_PAGE++;list.clear();int lenth =array.length();for(int i = 0;i<lenth;i++){list.add(array.optJSONObject(i));}}} catch (JSONException e) {e.printStackTrace();}}class HomeAdapter extends BaseAdapter {private Context context;private LayoutInflater inflater;private List<JSONObject> list;public HomeAdapter(Context context, List<JSONObject> list) {super();this.context = context;this.list = list;this.inflater = LayoutInflater.from(context);}@Overridepublic int getCount() {return list.size();}@Overridepublic Object getItem(int position) {return list.get(position);}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(final int position, View convertView, ViewGroup parent) {asyncImageLoader = new AsyncImageLoader();HomeViewHolder viewHolder = new HomeViewHolder();JSONObject data = (JSONObject)list.get(position);JSONObject source = null;convertView = inflater.inflate(R.layout.home_list_item, null);try {source = data.getJSONObject("source");} catch (JSONException e1) {e1.printStackTrace(); }viewHolder.home_headicon = (ImageView) convertView.findViewById(R.id.home_headicon);viewHolder.home_nick = (TextView) convertView.findViewById(R.id.home_nick);viewHolder.home_hasimage = (ImageView) convertView.findViewById(R.id.home_hasimage);viewHolder.home_timestamp = (TextView) convertView.findViewById(R.id.home_timestamp);viewHolder.home_origtext = (TextView) convertView.findViewById(R.id.home_origtext);viewHolder.home_source = (TextView) convertView.findViewById(R.id.home_source);if(data!=null){try {convertView.setTag(data.get("id"));//viewHolder.home_headicon.setImageDrawable(ImageUtil.getDrawableFromUrl(data.getString("head")+"/100"));//同步加载图片viewHolder.home_nick.setText(data.getString("nick"));viewHolder.home_timestamp.setText(TimeUtil.converTime(Long.parseLong(data.getString("timestamp"))));//viewHolder.home_origtext.setText(data.getString("origtext"), TextView.BufferType.SPANNABLE);/*Spannable spannable = (Spannable)viewHolder.home_origtext.getText();//加高亮显示spannable.setSpan(new BackgroundColorSpan(Color.RED), 0, 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);*/SpannableString spannable = new SpannableString(data.getString("origtext"));//把字符串解析成本地表情spannable = TextUtil.getImageSpannableString(spannable, RegexUtil.getStartAndEndIndex(data.getString("origtext"), Pattern.compile("\\/[\u4e00-\u9fa5a-zA-Z]{1,3}")), getResources());viewHolder.home_origtext.setText(spannable);if(source!=null){viewHolder.home_source.setText(source.getString("nick")+":"+source.getString("origtext"));viewHolder.home_source.setBackgroundResource(R.drawable.home_source_bg);}//异步加载图片Drawable cachedImage = asyncImageLoader.loadDrawable(data.getString("head")+"/100",viewHolder.home_headicon, new ImageCallback(){ @Override public void imageLoaded(Drawable imageDrawable,ImageView imageView, String imageUrl) { imageView.setImageDrawable(imageDrawable); } });if (cachedImage == null) {viewHolder.home_headicon.setImageResource(R.drawable.icon);} else {viewHolder.home_headicon.setImageDrawable(cachedImage);}if(data.getJSONArray("image")!=null){viewHolder.home_hasimage.setImageResource(R.drawable.hasimage);}} catch (JSONException e) {e.printStackTrace();} catch (Exception e) {e.printStackTrace();}}return convertView;}}static class HomeViewHolder {private ImageView home_headicon;private TextView home_nick;private TextView home_timestamp;private TextView home_origtext;private TextView home_source;private ImageView home_hasimage;}@Overridepublic boolean onItemLongClick(AdapterView<?> arg0, View arg1, int position,long arg3) {CharSequence [] items = null;try {items= new CharSequence[]{"转播","对话","点评","收藏",((JSONObject)array.opt(position)).getString("nick"),"取消"};} catch (JSONException e) {e.printStackTrace();}new AlertDialog.Builder(HomeTimeLineActivity.this).setTitle("选项").setItems(items,new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {switch (which) {case 0: {}break;case 1: {}break;case 2: {}break;case 3: {}break;case 4: {}break;case 5: {}break;default:break;}}}).show();return false;}@Overridepublic void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {JSONObject weiboInfo = (JSONObject)array.opt(position);Intent intent = new Intent(HomeTimeLineActivity.this, WeiboDetailActivity.class);try {intent.putExtra("weiboid", weiboInfo.getString("id"));startActivity(intent);} catch (JSONException e) {e.printStackTrace();}}@Overridepublic boolean onCreateOptionsMenu(Menu menu){super.onCreateOptionsMenu(menu);MenuInflater menuInflater = getMenuInflater();menuInflater.inflate(R.menu.home_timeline_menu, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {switch (item.getItemId()) {case R.id.menu_settings: {}break;case R.id.menu_official: {}break;case R.id.menu_feedback: {}break;case R.id.menu_account: {Intent intent = new Intent(HomeTimeLineActivity.this,AccountActivity.class);startActivity(intent);}break;case R.id.menu_about: {Intent intent = new Intent(HomeTimeLineActivity.this,AddWeiboActivity.class);startActivity(intent);}break;case R.id.menu_quit: {}break;default:break;}return true;}}

下面的布局文件是你所看见的更多提示和下方的进度条布局文件：

?
      ···········