能够兼容ViewPager的ScrollView

当ScrollView和ViewPager嵌套使用时，两者或发生滑动冲突，这时我们需要重新ScrollView。

public class ScollViewExtend extends ScrollView {
    // 滑动距离及坐标
    private float xDistance, yDistance, xLast, yLast;

    public ScollViewExtend(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                xDistance = yDistance = 0f;
                xLast = ev.getX();
                yLast = ev.getY();
                break;
            case MotionEvent.ACTION_MOVE:
                final float curX = ev.getX();
                final float curY = ev.getY();

                xDistance += Math.abs(curX - xLast);
                yDistance += Math.abs(curY - yLast);
                xLast = curX;
                yLast = curY;

                if(xDistance > yDistance){
                    return false;
                }
        }

        return super.onInterceptTouchEvent(ev);
    }
} 

重写onInterceptTouchEvent方法的方式也同样适用于解决ViewPager的ListView的兼容问题