ListView的动态加载效果

 

package com.src.hero;    import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.view.Gravity; import android.view.View; import android.view.ViewGroup; import android.view.ViewGroup.LayoutParams; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.BaseAdapter; import android.widget.LinearLayout; import android.widget.ListView; import android.widget.ProgressBar; import android.widget.TextView; import android.widget.Toast; /**  * @author Hero  * 2012-3-8 下午11:04:21  * 实现动态加载的效果  */ public class DynamicLoadActivity extends Activity {     private ListView lv_main;     private LinearLayout linearlayout = null;     private LayoutParams wlayoutparams, flayoutparams;     listAdapter adpter = null;     Thread thread;        /** Called when the activity is first created. */     @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);         lv_main = (ListView) findViewById(R.id.listView1);         adpter = new listAdapter(this);         wlayoutparams = new LinearLayout.LayoutParams(320, 50);// 定义的是FootView的宽高         flayoutparams = new LinearLayout.LayoutParams(                 LinearLayout.LayoutParams.WRAP_CONTENT,                 LinearLayout.LayoutParams.WRAP_CONTENT);// 定义FootView中控件的布局         ProgressBar progressbar = new ProgressBar(this);// 定义一个ProgressBar         progressbar.setPadding(50, 0, 0, 0);// left, top, right, bottom         TextView tv_wait = new TextView(this);// 定义一个TextView         tv_wait.setText("正在动态加载……");         tv_wait.setTextSize(20f);         tv_wait.setGravity(Gravity.CENTER_VERTICAL);         tv_wait.setPadding(10, 0, 0, 0);         LinearLayout layout = new LinearLayout(this);         layout.setOrientation(LinearLayout.HORIZONTAL);         layout.addView(progressbar, flayoutparams);         layout.addView(tv_wait, flayoutparams);         layout.setGravity(Gravity.CENTER);         linearlayout = new LinearLayout(this);         linearlayout.addView(layout, wlayoutparams);         linearlayout.setGravity(Gravity.CENTER_VERTICAL);         lv_main.addFooterView(linearlayout);         lv_main.setAdapter(adpter);         lv_main.setOnScrollListener(scroller);     }     /**      * 滚动监听器      */     OnScrollListener scroller = new OnScrollListener() {         @Override         public void onScroll(AbsListView view, int firstVisibleItem,                 int visibleItemCount, int totalItemCount) {             // TODO Auto-generated method stub             if (firstVisibleItem + visibleItemCount == totalItemCount) {                 // 启动一个线程去加载网络数据                 if (thread == null || !thread.isAlive()) {                     thread = new Thread() {                         @Override                         public void run() {                             try {                                 // 处理网络方法,在这里用线程休眠3秒方法来处理                                 Thread.sleep(3000);                             } catch (InterruptedException e) {                                 e.printStackTrace();                             }                             Message message = new Message();                             message.what = 1;                             handler.sendMessage(message);                         }                     };                     thread.start();                 }             }         }            @Override         public void onScrollStateChanged(AbsListView view, int scrollState) {             // TODO Auto-generated method stub            }        };     /**      * 消息队列      */     private Handler handler = new Handler() {         @Override         public void handleMessage(Message msg) {             // TODO Auto-generated method stub             switch (msg.what) {             case 1:                 if (adpter.count <= 101) {                     adpter.count += 10;                     int currentPage = adpter.count / 10;                     Toast.makeText(getApplicationContext(),                             "第" + currentPage + "页", Toast.LENGTH_LONG).show();                 } else {                     lv_main.removeFooterView(linearlayout);                 }                 // 重新刷新Listview的adapter里面数据                 adpter.notifyDataSetChanged();                 break;             default:                 break;             }         }     };        public class listAdapter extends BaseAdapter {            int count = 10;         Context context;            public listAdapter(Context context) {             this.context = context;         }            @Override         public int getCount() {             // TODO Auto-generated method stub             return count;         }            @Override         public Object getItem(int position) {             // TODO Auto-generated method stub             return position;         }            @Override         public long getItemId(int item) {             // TODO Auto-generated method stub             return item;         }            @Override         public View getView(int position, View convertView, ViewGroup parent) {             // TODO Auto-generated method stub             TextView tv_content;             if (convertView == null) {                 tv_content = new TextView(context);             } else {                 tv_content = (TextView) convertView;             }             tv_content.setText("Item     " + position);             tv_content.setTextSize(20f);//字体的大小20f             tv_content.setGravity(Gravity.CENTER);//显示在中间             tv_content.setHeight(50);//高度为50             return tv_content;         }        } }