Android ListView 的動態加載數據

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
實現動態加載的效果
*/
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);// 定義的是FootView的寬高
 flayoutparams = new LinearLayout.LayoutParams(
         LinearLayout.LayoutParams.WRAP_CONTENT,
         LinearLayout.LayoutParams.WRAP_CONTENT);// 定義FootView中控件的布局
 ProgressBar progressbar = new ProgressBar(this);// 定義一個ProgressBar
 progressbar.setPadding(50, 0, 0, 0);// left, top, right, bottom
 TextView tv_wait = new TextView(this);// 定義一個TextView
 tv_wait.setText("正在動態加載……");
 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);

}
 /**

滾動監聽器
*/
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) {
     // 啟動一個線程去加載網絡數據
     if (thread == null || !thread.isAlive()) {
         thread = new Thread() {
             @Override
             public void run() {
                 try {
                     // 處理網絡方法,在這里用線程休眠3秒方法來處理
                     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


}
};
/**

消息隊列
*/
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 + "頁", Toast.LENGTH_LONG).show();
     } else {
         lv_main.removeFooterView(linearlayout);
     }
     // 重新刷新Listview的adapter里面數據
     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);//字體的大小20f
 tv_content.setGravity(Gravity.CENTER);//顯示在中間
 tv_content.setHeight(50);//高度為50
 return tv_content;

}
}
}</pre>