android - Recyclerview：监听填充点击事件

Question

我有一个水平RecyclerView的leftPadding = 48dp,topPadding = 24dp和clipToPadding = false。它从左侧的空白区域开始，但是当用户滚动列表时，它的项目被绘制在那个（以前是空白的）空间上。顶部空间始终是空的。

这RecyclerView是在带有foreground = selectableItemBackground.

我的问题来自这样一个事实，即RecyclerView消耗和忽略左侧和顶部空间的触摸，这意味着在附加到或OnClickListener时都不会触发.FrameLayoutRecyclerView

我已经在clickable = false和focusable = false上尝试过RecyclerView，它不起作用。

我在找什么：

1. 可滚动RecyclerView
2. 可点击RecyclerView项目
3. FrameLayoutRecyclerView's单击空白区域时的单击事件
4. （替代 3）可点击的RecyclerView's空白区域

编辑：我创建了一个简单的项目来显示我正在谈论的问题：https ://github.com/dadino/recyclerviewemptyspacestest 有 2 个提交，在第一个提交时，我尝试捕获对父视图的点击，在第二个中，我尝试捕捉对 RecyclerView 本身的点击。它们都不起作用。

Answer 1

您必须创建自定义RecyclerView实现，您将在其中侦听触摸事件并基于此执行过滤。

class MyRecyclerView @JvmOverloads constructor(
        context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : RecyclerView(context, attrs, defStyleAttr) {

    private var isValid = false
    private var x: Int = 0
    private var y: Int = 0
    // this will help us to understand whether the event can be considered a touch or scroll
    private val delta: Int = ViewConfiguration.get(getContext()).scaledTouchSlop

    override fun onTouchEvent(e: MotionEvent?): Boolean {
        val onTouchEvent = super.onTouchEvent(e)
        when (e?.action) {
            MotionEvent.ACTION_DOWN -> {
                // saving initial touch location
                x = e.rawX.toInt()
                y = e.rawY.toInt()
                isValid = true
            }
            MotionEvent.ACTION_MOVE -> {
                if (Math.abs(e.rawX - x) > delta ||
                        Math.abs(e.rawY - y) > delta) {
                    // if a scroll happens - no longer consider this movement as valid
                    // this is needed for handling scroll on the inner part of `RecyclerView`                            
                    isValid = false
                }
            }
            MotionEvent.ACTION_UP -> {
                if (isValid && Math.abs(e.rawX - x) < delta &&
                        Math.abs(e.rawY - y) < delta &&
                        isInRightArea(e)) {
                    // 1. if the movement is still valid
                    // 2. we have actually performed a click                            
                    // 3. the click is in expected rectangle
                    // then perform click
                    performClick()
                }
            }
        }
        return onTouchEvent
    }

    // This is needed in order to handle the edge case, when a click listener 
    // would be fired when performing a click between the items of `RecyclerView`
    private fun isInRightArea(e: MotionEvent): Boolean {
        val r = Rect()
        getGlobalVisibleRect(r)
        r.left = paddingLeft
        r.top = r.top + paddingTop
        return !r.contains(e.rawX.toInt(), e.rawY.toInt())
    }

}

结果：