ScrollView滑動到最底端或者最頂端再載入資料

要實現一個功能：當Scrollview滑動到最底端的時候需要觸發事件載入其他資料。很多人都以為ScrollView可以像ListViev那樣setOnScrollListener，其實沒那麼簡單，因為ScrollView壓根就沒有該介面，在baidu上兜了一圈沒有找到合適的答案，沒辦法只能google去了，居然一下子解決了這個問題，還是老外比較牛，呵呵，這是我訪問的網址： 
http://stackoverflow.com/questions/2864563/how-do-i-know-that-the-scrollview-is-already-scrolled-to-the-bottom 

注意，如果資料不滿一頁的話，會執行onBottom方法！通常要使用懶載入的話資料都會超過一頁，所以我沒仔細考慮這個問題！ 

我把ScrollView封裝成類了，源碼如下： 

package com.ql.view;import android.content.Context;import android.os.Handler;import android.os.Message;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.widget.ScrollView; public class LazyScrollView extends ScrollView{private static final String tag="LazyScrollView";private Handler handler;private View view;public LazyScrollView(Context context) {super(context);// TODO Auto-generated constructor stub}public LazyScrollView(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stub}public LazyScrollView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);// TODO Auto-generated constructor stub}//這個獲得總的高度public int computeVerticalScrollRange(){return super.computeHorizontalScrollRange();}public int computeVerticalScrollOffset(){return super.computeVerticalScrollOffset();}private void init(){this.setOnTouchListener(onTouchListener);handler=new Handler(){        @Overridepublic void handleMessage(Message msg) {// process incoming messages heresuper.handleMessage(msg);switch(msg.what){case 1:if(view.getMeasuredHeight() <= getScrollY() + getHeight()) {if(onScrollListener!=null){onScrollListener.onBottom();}}else if(getScrollY()==0){if(onScrollListener!=null){onScrollListener.onTop();}}else{if(onScrollListener!=null){onScrollListener.onScroll();}}break;default:break;}}        };}  OnTouchListener onTouchListener=new OnTouchListener(){@Overridepublic boolean onTouch(View v, MotionEvent event) {// TODO Auto-generated method stubswitch (event.getAction()) {case MotionEvent.ACTION_DOWN:break;case MotionEvent.ACTION_UP:if(view!=null&&onScrollListener!=null){handler.sendMessageDelayed(handler.obtainMessage(1), 200);}break;default:break;}return false;}        };        /**     * 獲得參考的View，主要是為了獲得它的MeasuredHeight，然後和捲軸的ScrollY+getHeight作比較。     */    public void getView(){    this.view=getChildAt(0);    if(view!=null){    init();    }    }        /**     * 定義介面     * @author admin     *     */    public interface OnScrollListener{    void onBottom();    void onTop();    void onScroll();    }    private OnScrollListener onScrollListener;    public void setOnScrollListener(OnScrollListener onScrollListener){    this.onScrollListener=onScrollListener;    }}

用的時候也很簡單，通常這樣使用：

scrollView=(LazyScrollView)findViewById(R.id.scrollView);        scrollView.getView();        scrollView.setOnScrollListener(new OnScrollListener() {@Overridepublic void onTop() {// TODO Auto-generated method stubLog.d(tag,"------滾動到最上方------");}@Overridepublic void onScroll() {// TODO Auto-generated method stubLog.d(tag,"沒有到最下方，也不是最上方");}@Overridepublic void onBottom() {// TODO Auto-generated method stubLog.d(tag,"------滾動到最下方------");}});