Gallery中的ScrollView，两者均独立滚动

本文介绍了Gallery中的ScrollView，两者均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图库，该适配器为其提供ScrollViews作为其子视图.我需要确保正确并按预期处理了触摸事件:

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，图库水平滚动.
当用户垂直滚动时，滚动视图垂直滚动.
两个滚动都不应该在同一手势上发生(用户必须抬起手指才能滚动另一个视图).
一切都必须顺畅滚动.

在不覆盖任何方法的情况下，滚动视图是唯一可滚动的内容-画廊永远不会滚动.

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(...)来决定接管一系列MotionEvent，但是我不确定如何检查触摸的本质是水平还是垂直.

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，经过一些重大摆弄和logcat黑客攻击之后，以下是解决方法:

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);
            }
        }
    }
}

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