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

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
老规矩，先上图
这张图片左边部分和右边部分还是有很大的不同，不是指内容上，是指布局上，左边的是我今天写这次代码之前的布局，root是用的RelativeLayout，右边是用的FrameLayout，体现在界面上就是右边的list内容可以顶到最上面，而左边的list是在上面的topBar下面。


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		@Override	protected 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() {			@Override			public void onClick(View v) {				Intent intent = new Intent(HomeTimeLineActivity.this,AddWeiboActivity.class);				startActivity(intent);			}		});		tv_msg.setOnClickListener(new OnClickListener() {			@Override			public 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TextView				loading.setVisibility(View.VISIBLE);//显示最下方的进度条			}		});	}		class GetHomeTimeLineHandler extends Handler {		@Override		public 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 {		@Override		public 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);		}		@Override		public int getCount() {			return list.size();		}		@Override		public Object getItem(int position) {			return list.get(position);		}		@Override		public long getItemId(int position) {			return position;		}		@Override		public 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;	}	@Override	public 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() {			@Override			public 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;	}	@Override	public 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();		}	}		@Override	public boolean onCreateOptionsMenu(Menu menu){		super.onCreateOptionsMenu(menu);		MenuInflater menuInflater = getMenuInflater();		menuInflater.inflate(R.menu.home_timeline_menu, menu);		return true;	}		@Override	public 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：

<?xml version="1.0" encoding="UTF-8"?><LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:minHeight="?android:listPreferredItemHeight"  xmlns:android="http://schemas.android.com/apk/res/android">    <TextView android:textSize="16.0sp" android:textColor="#ff545454" android:gravity="center" android:id="@id/tv_msg" android:layout_width="fill_parent" android:layout_height="fill_parent" android:text="更多"/>    <LinearLayout android:gravity="center" android:layout_gravity="center" android:orientation="horizontal" android:id="@id/loading" android:layout_width="fill_parent" android:layout_height="fill_parent">        <ProgressBar android:layout_gravity="center_vertical" android:id="@id/footprogress" android:layout_width="wrap_content" android:layout_height="wrap_content" android:indeterminateBehavior="repeat" style="?android:progressBarStyleSmallInverse" />        <TextView android:textColor="#ff000000" android:gravity="left|center" android:padding="3.0px" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="读取中" />    </LinearLayout></LinearLayout>