[移动开发]Android 滑动冲突（内部，外部拦截）

?外部拦截法

@Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        boolean intercepted =false;
        int x = (int) ev.getX();
        int y = (int) ev.getY();
        switch (ev.getAction()){
            case MotionEvent.ACTION_DOWN:
                intercepted = false;
                break;
            case MotionEvent.ACTION_MOVE:
                if(父容器需要当前点击事件) {
                    intercepted = true;
                }else {
                    intercepted = false;
                }
                
                break;
            case MotionEvent.ACTION_UP:
                intercepted = false;
                break;
            default:
                break;
        }
        mLastXintercept = x;
        mLastYintercept = y;
        return intercepted;
    }

其中ACTION_DOWN事件必须返回false，因为父容器一旦拦截就无法传递到子元素了，最后是ACTION_UP事件返回false，父容器拦截move，up事件也会拦截

内部拦截法

@Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        int x = (int) ev.getX();
        int y = (int) ev.getY();
        switch (ev.getAction()){
            case MotionEvent.ACTION_DOWN:
                parent.requestDisallowInterceptTouchEvent(true);
                break;
            case MotionEvent.ACTION_MOVE:
                int delatX = x - mLastX;
                int delatY = y - mLastY;
                if(父容器需要) {
                    parent.requestDisallowInterceptTouchEvent(false);
                }
                break;
            case MotionEvent.ACTION_UP:
                
                break;
            default:
                break;
        }
        mLastX = x;
        mLastY = y;
        return intercepted;
    }

父容器也要拦截除了ACTION_DOWN以外的事件，这样子元素调用

parent.requestDisallowInterceptTouchEvent(false);时，父元素才能继续拦截所需事件

而ACTION_DOWN事件不受这个标记位影响，所以父容器一旦拦截ACTION_DOWN，事件就无法传递到子元素中了