自定义ScrollView

scrollview最外层，当滑动的距离到一定程度（阈值，可指定值）才拦截滑动事件，否则 其内部子控件消费滑动事件

public class MyScrollview extends ScrollView {
    private int downX;
    private int downY;
    private int mTouchSlop;

    public MyScrollview(Context context) {
    super(context);
    mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
   }

    public MyScrollview(Context context, AttributeSet attrs) {
    super(context, attrs);
    mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    }

    public MyScrollview(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    }

@Override
public boolean onInterceptTouchEvent(MotionEvent e) {
    int action = e.getAction();
    switch (action) {
        case MotionEvent.ACTION_DOWN:
            downX = (int) e.getRawX();
            downY = (int) e.getRawY();
            break;
        case MotionEvent.ACTION_MOVE:
            int moveY = (int) e.getRawY();
            if (Math.abs(moveY - downY) > mTouchSlop) {
                return true;
            }
    }
    return super.onInterceptTouchEvent(e);
}
}