Android ScrollView实现横向和竖向拖动回弹效果

 本文实例为大家分享了Android ScrollView实现拖动回弹效果的具体代码，供大家参考，具体内容如下

原理

在android2.3版本中，View类中新增了一个方法：overScrollBy。通过覆盖该方法，就可以达到阻尼回弹的效果。

示例1、竖向滚动 

public class ReboundScrollView extends ScrollView{ 
 private static final int MAX_SCROLL = 200; 
 private static final float SCROLL_RATIO = 0.5f;// 阻尼系数 
  
 public ReboundScrollView(Context context) 
 { 
  super(context); 
 } 
 
 public ReboundScrollView(Context context, AttributeSet attrs) 
 { 
  super(context, attrs); 
 } 
 
 public ReboundScrollView(Context context, AttributeSet attrs, int defStyle) 
 { 
  super(context, attrs, defStyle); 
 } 
  
 @Override 
 protected boolean overScrollBy(int deltaX, int deltaY, int scrollX, int scrollY, int scrollRangeX, int scrollRangeY, int maxOverScrollX, int maxOverScrollY, boolean isTouchEvent) 
 {  
  int newDeltaY = deltaY; 
  int delta = (int) (deltaY * SCROLL_RATIO); 
  if((scrollY+deltaY)==0 || (scrollY-scrollRangeY+deltaY)==0){ 
   newDeltaY = deltaY;  //回弹最后一次滚动，复位 
  }else{ 
   newDeltaY = delta;  //增加阻尼效果 
  } 
  return super.overScrollBy(deltaX, newDeltaY, scrollX, scrollY, scrollRangeX, scrollRangeY, maxOverScrollX, MAX_SCROLL, isTouchEvent);  
 } 
} 

示例2、横向滚动

public class ReboundHScrollView extends HorizontalScrollView{ 
 private static final int MAX_SCROLL = 200; 
 private static final float SCROLL_RATIO = 0.5f;// 阻尼系数 
  
 public ReboundHScrollView(Context context) 
 { 
  super(context); 
 } 
 
 public ReboundHScrollView(Context context, AttributeSet attrs) 
 { 
  super(context, attrs); 
 } 
 
 public ReboundHScrollView(Context context, AttributeSet attrs, int defStyle) 
 { 
  super(context, attrs, defStyle); 
 } 
  
 @Override 
 protected boolean overScrollBy(int deltaX, int deltaY, int scrollX, int scrollY, int scrollRangeX, int scrollRangeY, int maxOverScrollX, int maxOverScrollY, boolean isTouchEvent) 
 {  
  int newDeltaX = deltaX; 
  int delta = (int) (deltaX * SCROLL_RATIO); 
  if((scrollX+deltaX)==0 || (scrollX-scrollRangeX+deltaX)==0){ 
   newDeltaX = deltaX;  //回弹最后一次滚动，复位 
  }else{ 
   newDeltaX = delta;  //增加阻尼效果 
  } 
  return super.overScrollBy(newDeltaX, deltaY, scrollX, scrollY, scrollRangeX, scrollRangeY, MAX_SCROLL, maxOverScrollY, isTouchEvent);  
 } 
} 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持自由互联。