Question

我从这里创建了这个自定义ViewPager（Android: Vertical ViewPager）：

class VerticalViewPager : ViewPager {

@JvmOverloads
constructor(
        context: Context,
        attrs: AttributeSet? = null)
        : super(context, attrs){
    setPageTransformer(false, DefaultTransformer())
    overScrollMode = OVER_SCROLL_NEVER
}

override fun onInterceptTouchEvent(ev: MotionEvent): Boolean {
    val intercepted = super.onInterceptTouchEvent(swapXY(ev))
    swapXY(ev) // return touch coordinates to original reference frame for any child views
    return intercepted
}

override fun onTouchEvent(ev: MotionEvent?): Boolean {
    return super.onTouchEvent(ev)
}

/**
 * Swaps the X and Y coordinates of your touch event.
 */
private fun swapXY(ev: MotionEvent): MotionEvent {
    val width = width.toFloat()
    val height = height.toFloat()

    val newX = ev.y / height * width
    val newY = ev.x / width * height

    ev.setLocation(newX, newY)

    return ev
}

private class VerticalPageTransformer : ViewPager.PageTransformer{
    override fun transformPage(view: View, position: Float) {
        if (position < -1) { // [-Infinity,-1)
            // This page is way off-screen to the left.
            view.alpha = 0f

        } else if (position <= 1) { // [-1,1]
            view.alpha = 1f

            // Counteract the default slide transition
            view.translationX = view.getWidth() * -position

            //set Y position to swipe in from top
            val yPosition = position * view.getHeight()
            view.translationY = yPosition

        } else { // (1,+Infinity]
            // This page is way off-screen to the right.
            view.alpha = 0f
        }
    }

}

}

我使用一个在每个页面内加载ImageView的适配器。此ImageView有一个onClickListener。

open class VerticalViewPagerAdapter(var mContext: Context, val photos : RealmList<ProfilePhoto>?, onPhotoClick: OnPhotoClick?) : PagerAdapter() {

var mLayoutInflater : LayoutInflater? = null
val onPhotoListener = onPhotoClick

init {
    mLayoutInflater = mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater
}

override fun getCount(): Int {
    return photos?.size!!
}

override fun isViewFromObject(view: View, `object`: Any): Boolean {
    return view === `object` as FrameLayout
}

override fun instantiateItem(container: ViewGroup, position: Int): Any {
    val itemView = mLayoutInflater?.inflate(R.layout.view_image_profile_viewpager_item, container, false)

    val imageView = itemView?.findViewById(R.id.profileImageItemIv) as ImageView

    imageView.setOnClickListener{
        onPhotoListener?.onPhotoClick(position)
    }

    imageView.loadUrlImage(photos!![position]?.photo)

    container.addView(itemView)

    return itemView
}

override fun destroyItem(container: ViewGroup, position: Int, `object`: Any) {
    container.removeView(`object` as FrameLayout)
}
}

如果ImageView具有此侦听器，则自定义viewpager上的滑动不起作用。如果我删除了监听器，则工作正常。

有人知道会出现什么问题吗？

Answer 1

最后我解决了这个问题。我是在onInterceptTouchEvent中添加逻辑来释放onTouch事件，如果用户只点击viewpager而不是交换。这是最终的代码：

class VerticalViewPager : ViewPager {

var originalPosY = 0

@JvmOverloads
constructor(
        context: Context,
        attrs: AttributeSet? = null)
        : super(context, attrs){
    setPageTransformer(false, DefaultTransformer())
}

private fun swapTouchEvent(event: MotionEvent): MotionEvent {
    val width = width.toFloat()
    val height = height.toFloat()

    val swappedX = event.y / height * width
    val swappedY = event.x / width * height

    event.setLocation(swappedX, swappedY)

    return event
}

override fun onInterceptTouchEvent(event: MotionEvent): Boolean {

    var y : Int = event.rawY.toInt()

    return when (event.action) {

        MotionEvent.ACTION_DOWN -> {
            originalPosY = y
            val intercept = super.onInterceptTouchEvent(swapTouchEvent(event))
            swapTouchEvent(event)
            false
        }

        MotionEvent.ACTION_MOVE -> {

            val intercept = super.onInterceptTouchEvent(swapTouchEvent(event))
            val i = swapTouchEvent(event)
            true

        }

        MotionEvent.ACTION_UP -> {

            if (Math.abs(originalPosY - y) > 10) {
                super.onInterceptTouchEvent(swapTouchEvent(event))
                val i = swapTouchEvent(event)
                true
            }else
                false
        }

        else -> super.onInterceptTouchEvent(swapTouchEvent(event))

    }
}

override fun onTouchEvent(event: MotionEvent): Boolean = super.onTouchEvent(swapTouchEvent(event))
}

结果并非完全符合我的要求。如果有人可以改进它，那将是受欢迎的

自定义垂直viewpager无法与子视图上的onClick侦听器一起使用

1 个答案: