列表的上下左右滑动在实际开发中应用场景比较多的地方，比如， 股票列表， 基金列表
先看一张效果图， 只是一张静态图片
实现方案， RecycleView + HorizontalScrollView
优势
支持任意类型的UI, 只需要在ViewHolder里面定义自己想要的效果即可
实现原理
1、 自定义RecycleView
2、 自定义了HorizontalScrollView
3、 ViewHolder里面的View,添加进入RecycleView的时候做了拦截。将ViewHolder持有的View,在外面在包装一层HorizontalScrollView
4、 拦截RecycleView的addView方法
5、 重写HorizontalScrollView里面的 dispatchTouchEvent方法， onScrollChanged方法， onTouchEvent方法， fling方法
6、将添加进RecycleView里面的HorizontalScrollView 用集合保存起来， 目的就是当有一个scrollView左右滑动的时候， 调用其它的scrollView也相应的左右滑动。
贴上具体的源码
package com.richzjc.lib
import android.content.Context
import android.text.TextUtils
import android.util.AttributeSet
import android.view.MotionEvent
import android.view.View
import android.view.ViewGroup
import android.widget.HorizontalScrollView
import android.widget.OverScroller
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import kotlinx.coroutines.delay
import java.lang.reflect.Field
import java.lang.reflect.Method
class FundRankRecycleView @JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : RecyclerView(context, attrs, defStyleAttr) {
init {
layoutManager = LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false)
}
val scrollViews by lazy { ArrayList<RankHorizontalScrollView>() }
var maxScrollX: Int = 0
override fun addView(child: View?, index: Int, params: ViewGroup.LayoutParams?) {
val rightScroll = child?.findViewById<View>(R.id.right_scroll)
if (rightScroll == null || rightScroll.parent is RankHorizontalScrollView) {
super.addView(child, index, params)
} else {
val group = rightScroll.parent as ViewGroup
val tempParams = ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT)
val scrollView =
RankHorizontalScrollView(
this,
context
)
group.removeView(rightScroll)
scrollView.tag = child
scrollView.addView(rightScroll, tempParams)
group.addView(scrollView, tempParams)
super.addView(child, index, params)
requestData {
do {
scrollView.scrollTo(maxScrollX, 0)
delay(20)
} while (scrollView.scrollX < maxScrollX)
}
}
}
class RankHorizontalScrollView @JvmOverloads constructor(var recycleView: FundRankRecycleView,
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : HorizontalScrollView(context, attrs, defStyleAttr) {
private var moveFlag = false
private var scrollerField: Field? = null
private var findMethod: Method? = null
private var downX : Float = 0f
init {
overScrollMode = View.OVER_SCROLL_NEVER
scrollerField = javaClass.superclass?.getDeclaredField("mScroller")?.apply { isAccessible = true }
initMethod()
}
private fun initMethod() {
javaClass.superclass?.declaredMethods?.forEach {
if (TextUtils.equals("findFocusableViewInMyBounds", it.name)) {
findMethod = it
findMethod?.isAccessible = true
return@forEach
}
}
}
override fun onAttachedToWindow() {
super.onAttachedToWindow()
if (!recycleView.scrollViews.contains(this))
recycleView.scrollViews?.add(this)
scrollTo(recycleView.maxScrollX, 0)
}
override fun dispatchTouchEvent(ev: MotionEvent?): Boolean {
when (ev?.action) {
MotionEvent.ACTION_DOWN -> moveFlag = true
MotionEvent.ACTION_MOVE -> moveFlag = true
else -> moveFlag = false
}
return super.dispatchTouchEvent(ev)
}
override fun onScrollChanged(l: Int, t: Int, oldl: Int, oldt: Int) {
super.onScrollChanged(l, t, oldl, oldt)
recycleView.maxScrollX = scrollX
recycleView.scrollViews?.forEach {
if (it != this@RankHorizontalScrollView && moveFlag)
it.scrollTo(recycleView.maxScrollX, 0)
}
}
override fun onTouchEvent(ev: MotionEvent?): Boolean {
if (ev?.action == MotionEvent.ACTION_DOWN) {
(tag as? View)?.onTouchEvent(ev)
downX = ev.x
var mScroller: OverScroller?
recycleView.scrollViews?.forEach {
mScroller = scrollerField?.get(it) as? OverScroller
if (mScroller != null && !mScroller!!.isFinished) {
mScroller?.abortAnimation()
}
}
recycleView.maxScrollX = scrollX
} else if (ev?.action == MotionEvent.ACTION_MOVE) {
(tag as? View)?.onTouchEvent(ev)
if(scrollX == 0 && (ev.x > downX))
return false
else if(scrollX == (getChildAt(0).width - width) && (ev.x < downX))
return false
}else if(ev?.action == MotionEvent.ACTION_UP){
if(kotlin.math.abs(ev.x - downX) < ScreenUtils.dip2px(10f, context))
(tag as? View)?.onTouchEvent(ev)
}else{
(tag as? View)?.onTouchEvent(ev)
}
return super.onTouchEvent(ev)
}
override fun fling(velocityX: Int) {
recycleView.scrollViews.forEach {
if (it.childCount > 0) {
val width: Int = it.width - it.paddingRight - it.paddingLeft
val right = it.getChildAt(0).width
val mScroller = scrollerField?.get(it) as? OverScroller
if (mScroller != null) {
mScroller.fling(it.scrollX, it.scrollY, velocityX, 0, 0,
Math.max(0, right - width), 0, 0, width / 2, 0)
val movingRight = velocityX > 0
val currentFocused = it.findFocus()
var newFocused = findMethod?.invoke(it, movingRight, mScroller.finalX, currentFocused) as? View
if (newFocused == null) {
newFocused = it
}
if (newFocused !== currentFocused) {
newFocused.requestFocus(if (movingRight) View.FOCUS_RIGHT else View.FOCUS_LEFT)
}
it.postInvalidateOnAnimation()
}
}
}
}
override fun onDetachedFromWindow() {
super.onDetachedFromWindow()
recycleView.scrollViews?.remove(this)
}
}
}
备注
- 如果有何不明白的地方可以私信我 （QQ: 861667050）
- 如果有更好的实现方案，可以一起探讨
- 以上的实现方案，是我自己写的，没有参考别人的。 网上的实现方案也很多， 熟优熟劣，我也不清楚。
- 记录下面用于共同学习进步
