Gallery 内的 ScrollView，两者都独立滚动

本文介绍了Gallery 内的 ScrollView，两者都独立滚动的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个带有适配器的 Gallery，它提供 ScrollViews 作为它的子视图.我需要确保按预期正确处理触摸事件:

I have a Gallery with an adapter which supplies it ScrollViews as its child views. I need to make sure that the touch events are handled correctly and as expected:

当用户水平滚动时，图库也会水平滚动.

当用户垂直滚动时，滚动视图也会垂直滚动.

绝不能在同一个手势上进行两次滚动(用户必须抬起手指才能滚动另一个视图).

一切都必须平滑滚动.

在不覆盖任何方法的情况下，滚动视图是唯一滚动的东西 - 图库从不滚动.

Without overriding any methods, the scroll view is the only thing that scrolls - the gallery never scrolls.

所以我知道我需要在图库中使用 onInterceptTouchEvent(...) 来决定接管某个系列的 MotionEvents，但我不确定如何检查触摸是水平的还是垂直的.

So I understand I need to use onInterceptTouchEvent(...) in the gallery to decide to take over a certain series of MotionEvents but I am unsure how to check if the touch is horizontal or vertical in nature.

推荐答案

好的，经过一些主要的摆弄和 logcat hacking，这里是解决方案:

OK, after some major fiddling and logcat hacking, here's the solution:

public class SwipeInterceptingGallery extends Gallery { private float mInitialX; private float mInitialY; private boolean mNeedToRebase; private boolean mIgnore; public SwipeInterceptingGallery(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } public SwipeInterceptingGallery(Context context, AttributeSet attrs) { super(context, attrs); } public SwipeInterceptingGallery(Context context) { super(context); } @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { if (mNeedToRebase) { mNeedToRebase = false; distanceX = 0; } return super.onScroll(e1, e2, distanceX, distanceY); } @Override public boolean onInterceptTouchEvent(MotionEvent e) { switch (e.getAction()) { case MotionEvent.ACTION_DOWN: { mIgnore = false; mNeedToRebase = true; mInitialX = e.getX(); mInitialY = e.getY(); return false; } case MotionEvent.ACTION_MOVE: { if (!mIgnore) { float deltaX = Math.abs(e.getX() - mInitialX); float deltaY = Math.abs(e.getY() - mInitialY); mIgnore = deltaX < deltaY; return !mIgnore; } return false; } default: { return super.onInterceptTouchEvent(e); } } } }