ScrollView重写实现监听

  1 package com.ft.mysinaweibo;
  2 
  3 import java.lang.reflect.Field;
  4 import java.lang.reflect.Method;
  5 
  6 import android.content.Context;
  7 import android.os.Handler;
  8 import android.util.AttributeSet;
  9 import android.util.Log;
 10 import android.view.GestureDetector;
 11 import android.view.GestureDetector.SimpleOnGestureListener;
 12 import android.view.MotionEvent;
 13 import android.view.View;
 14 import android.webkit.WebView;
 15 import android.widget.AbsListView.OnScrollListener;
 16 import android.widget.ScrollView;
 17 import android.widget.Scroller;
 18 
 19 /**
 20  * 自定义ScrollView，解决： 1. ScrollView嵌套ViewPager，导致ViewPager不能滑动的问题 2.
 21  * ScrollView源码并没有实现滚动监听，所以我们必须自行实现对ScrollView的监听，
 22  * 我们很自然的想到在onTouchEvent()方法中实现对滚动Y轴进行监听 ScrollView的滚动Y值进行监听
 23  * 
 24  */
 25 public class CustomScrollView extends ScrollView {
 26     private GestureDetector mGestureDetector;
 27     private int Scroll_height = 0;
 28     private int view_height = 0;
 29     protected Field scrollView_mScroller;
 30     private static final String TAG = "CustomScrollView";
 31 
 32     private OnScrollListener onScrollListener;
 33     private int lastScrollY;// ScrollView在Y方向滑动的最后距离
 34 
 35     public CustomScrollView(Context context, AttributeSet attrs) {
 36         super(context, attrs);
 37         // mGestureDetector = new GestureDetector(context, new
 38         // YScrollDetector());
 39         setFadingEdgeLength(0);
 40     }
 41 
 42     // --------------------------------------------------------------------------//
 43     /**
 44      * 设置滚动接口
 45      * 
 46      * @param onScrollListener
 47      */
 48     public void setOnScrollListener(OnScrollListener onScrollListener) {
 49         this.onScrollListener = onScrollListener;
 50     }
 51 
 52     /**
 53      * 用于用户手指离开MyScrollView的时候获取MyScrollView滚动的Y距离，然后回调给onScroll方法中
 54      */
 55     private Handler handler = new Handler() {
 56 
 57         public void handleMessage(android.os.Message msg) {
 58             int scrollY = CustomScrollView.this.getScrollY();
 59 
 60             // 此时的距离和记录下的距离不相等，在隔5毫秒给handler发送消息
 61             if (lastScrollY != scrollY) {
 62                 lastScrollY = scrollY;
 63                 handler.sendMessageDelayed(handler.obtainMessage(), 5);
 64             }
 65             if (onScrollListener != null) {
 66                 onScrollListener.onScroll(scrollY);
 67             }
 68 
 69         };
 70 
 71     };
 72 
 73     /**
 74      * 滚动的回调接口
 75      */
 76     public interface OnScrollListener {
 77         /**
 78          * 回调方法， 返回MyScrollView滑动的Y方向距离
 79          */
 80         public void onScroll(int scrollY);
 81     }
 82 
 83     
 84     
 85     @Override
 86     public boolean onTouchEvent(MotionEvent ev) {
 87         int scrollY = getScrollY();
 88 
 89         // 此时的距离和记录下的距离不相等，在隔5毫秒给handler发送消息
 90         if (lastScrollY != scrollY) {
 91             lastScrollY = scrollY;
 92             handler.sendMessageDelayed(handler.obtainMessage(), 5);
 93         }
 94         if (onScrollListener != null) {
 95             onScrollListener.onScroll(scrollY);
 96         }
 97         return super.onTouchEvent(ev);
 98     }
 99 
100 }
101 
102
读好书，如同与先哲们交谈。