分页加载my

来源：互联网发布：中兴软件开发技术面编辑：程序博客网时间：2024/06/06 05:38

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;

public class MainActivity extends Activity {

   private ListView lv_main;
   private ProgressBar pb_main;
   private List<String> list;

   int index=0;
   int max=20;
   int progress=0;
   private ProgressDialog progressDialog;

   Handler handler=new Handler(){
       private ArrayAdapter<String> arrayAdapter;

       public void handleMessage(android.os.Message msg) {
           pb_main.setVisibility(View.GONE);
           progressDialog.dismiss();
           if(arrayAdapter==null){
               arrayAdapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_expandable_list_item_1, android.R.id.text1, list);
               lv_main.setAdapter(arrayAdapter);
           }else{
               arrayAdapter.notifyDataSetChanged();
           }
       };
   };

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);

       lv_main = (ListView) findViewById(R.id.lv_main);
       pb_main = (ProgressBar) findViewById(R.id.pb_main);

       list = new ArrayList<String>();
       //第一次进来加载数据
       loading();
       //监听listview
       listview_click();
   }

   //第一次进来加载数据
   private void loading() {
       progressDialog = new ProgressDialog(MainActivity.this);
       progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
       progressDialog.setTitle("正在加载数据");
       progressDialog.show();

       //子线程加载数据
       new Thread(){
           public void run() {
               //给集合添加数据
               for (int i = index; i < index+max; i++) {
                   list.add("盟"+i);
               }
               //progressdialog进度条加载
               while(progress<100){
                   progress++;
                   progressDialog.setProgress(progress);
                   try {
                       sleep(10);
                   } catch (InterruptedException e) {
                       // TODO Auto-generated catch block
                       e.printStackTrace();
                   }
               }
               if(progress==100){
                   //给handler发送message通知主线程处理UI更新操作
                   handler.sendEmptyMessage(0);
                   progress=0;
               }
           };
       }.start();
   }

   //监听listview
   private void listview_click() {
       // TODO Auto-generated method stub
       lv_main.setOnScrollListener(new OnScrollListener() {
           //滚动状态改变
           @Override
           public void onScrollStateChanged(AbsListView view, int scrollState) {
               // TODO Auto-generated method stub
               switch (scrollState) {
               //停止状态
               case OnScrollListener.SCROLL_STATE_IDLE:
                   //获取最后一个数值的position
                   int lastVisiblePosition = view.getLastVisiblePosition();
                   if(lastVisiblePosition==list.size()-1){
                       index=index+max;
                       pb_main.setVisibility(View.VISIBLE);
                       loading();
                   }

                   break;

               default:
                   break;
               }
           }

           @Override
           public void onScroll(AbsListView view, int firstVisibleItem,
                   int visibleItemCount, int totalItemCount) {
               // TODO Auto-generated method stub
               if(firstVisibleItem==0){
                   list.clear();
                   index=0;
                   max=20;
                   pb_main.setVisibility(View.VISIBLE);
                   loading();
               }
           }
       });
   }

}

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