ListView中运用线程实现无限加载

ListView中使用线程实现无限加载
footview的模版如下:  
 
  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
     android:orientation="horizontal"  
       android:layout_width="fill_parent"  
       android:gravity="center_horizontal"  
       android:padding="3dp"  
       android:layout_height="fill_parent">  
      
       <TextView  
           android:id="@id/android:empty"  
           android:layout_width="wrap_content"  
           android:layout_height="fill_parent"  
           android:gravity="center"  
           android:padding="5dp"  
           android:text="Loading more days..."/>        
 </LinearLayout>  
[代码] 然后记得在加到adapter前,把footview加到listview中去  
    View footerView = ((LayoutInflater)this.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.listfooter, null, false);  
       
    this.getListView().addFooterView(footerView);  
       
    this.setListAdapter(adapter);  
[代码] listview的onscroll方法如下  
   this.getListView().setOnScrollListener(new OnScrollListener(){  
                 
                     
               public void onScrollStateChanged(AbsListView view, int scrollState) {}  
                public void onScroll(AbsListView view, int firstVisibleItem,  
                       int visibleItemCount, int totalItemCount) {  
                     
                     
                                   int lastInScreen = firstVisibleItem + visibleItemCount;                
                   String last=Integer.toString(lastInScreen);  
                   Log.d("show",last);  
                   String total=Integer.toString(totalItemCount);  
                   Log.d("total",total);  
                                 
   if((lastInScreen == totalItemCount) && !(loadingMore)){                    
                       Thread thread =  new Thread(null, loadMoreListItems);  
                       thread.start();  
                   }  
               }  
           });  
             
             
                 
   Thread thread =  new Thread(null, loadMoreListItems);  
           thread.start();  
      
  /** 
   下面来分析下,其中,可以预先设置一个屏的listview能显示多少条记录,比如设置为5条, 
   这里itemsPerPage=15,然后首先 
   int lastInScreen = firstVisibleItem + visibleItemCount; 
     这里,获得每屏中最后一条数据的位置,比如一次先显示5条,则lastInScreen=5了, 
   */  
   if((lastInScreen == totalItemCount) && !(loadingMore)){  
   Thread thread =  new Thread(null, loadMoreListItems);  
           thread.start();  
   }  
   /** 
     这里是判断,如果是滚动了滚动条,并且用户以及功能浏览完了一次屏幕所需要的数目(比如5个),则启用线程序loadMoreListItems去处理,加载另外的新的5个了. 
   而如果没滚动,则第一次显示时,也要启用线程序loadMoreListItems去处理. 
   . 
     下面看loadMoreListItems. 
   */  
     private Runnable loadMoreListItems = new Runnable() {            
         
           public void run() {  
                          loadingMore = true;  
                
                          myListItems = new ArrayList<String>();  
                 
               //Simulate a delay, delete this on a production environment!  
             try { Thread.sleep(1000);  
              } catch (InterruptedException e) {}  
                 
               //Get 15 new listitems  
               for (int i = 0; i < itemsPerPage; i++) {        
                    
        myListItems.add("Date: " + (d.get(Calendar.MONTH)+ 1) + "/" + d.get(Calendar.DATE) + "/" + d.get(Calendar.YEAR) );                                          d.add(Calendar.DATE, 1);  
                     
              }  
                 
                          runOnUiThread(returnRes);  
                 
           }  
      };    
     
   /** 
   在这个线程里,实际上就是用循环往listview中加日期,产生从当天时间起的若干个日期格式,然后调用 runOnUiThread(returnRes);去更新UI主线程,注意 runOnUiThread是 
   android提供的方法,可以帮助你在线程中执行UI更新操作. 
     
   在更新主线程中,十分简单,只不过往adapter中去增加元素,并且notifyDataSetChanged通知listview起变化了, 
   并设置loadingMore=false,因为已经加载完了一次了. 
   */
ListView中运用线程实现无限加载

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