MultiType GridLayoutManager 间距问题
UI大致长这个样子，图片item之间的间距和文本item之间的间距不是一样的，稍微好一点的就是图片item和文本item到屏幕左右的间距是一样的。
可以通过GridLayoutManager.LayoutParams的getSpanIndex得到这个item在这一行是第几个
//图片item之间横向的间距 val imageSpan = Utils.convertDpToPixel(15f).toInt() //文字item之间横向的间距 val textSpan = Utils.convertDpToPixel(5f).toInt() //设置item之间的间距 val itemDecoration = object :ItemDecoration(){ override fun getItemOffsets(outRect: Rect,view: View,parent: RecyclerView,state: RecyclerView.State) { super.getItemOffsets(outRect, view, parent, state) val position = parent.getChildAdapterPosition(view) if(position >= 0 && position<items.size){ val item = items[position] if(item is TextBean){//文字的item if (parent.layoutManager is GridLayoutManager) { val spanIndex = (view.layoutParams as GridLayoutManager.LayoutParams).spanIndex val spanSize = (view.layoutParams as GridLayoutManager.LayoutParams).spanSize //item在该行是第几个 val indexInRow = spanIndex / spanSize val spanCount = 4 outRect.left = indexInRow * textSpan / spanCount outRect.right = textSpan - (indexInRow + 1) * textSpan / spanCount outRect.bottom = Utils.convertDpToPixel(5f).toInt() } }else if(item is ImageBean){//图片的item if (parent.layoutManager is GridLayoutManager) { val spanIndex = (view.layoutParams as GridLayoutManager.LayoutParams).spanIndex val spanSize = (view.layoutParams as GridLayoutManager.LayoutParams).spanSize //item在该行是第几个 val indexInRow = spanIndex / spanSize val spanCount = 3 outRect.left = indexInRow * imageSpan / spanCount outRect.right = imageSpan - (indexInRow + 1) * imageSpan / spanCount outRect.bottom = Utils.convertDpToPixel(20f).toInt() } }else{//标题 outRect.bottom = Utils.convertDpToPixel(20f).toInt() } } } } 复制代码这个Image的item是正方形的，通过ConstraintLayout的layout_constraintDimensionRatio属性设置为1：1
<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="wrap_content"> <ImageView android:id="@+id/thumbIv" android:layout_width="0dp" android:layout_height="0dp" android:scaleType="centerCrop" android:src="@mipmap/ic_place_holder" app:layout_constraintDimensionRatio="1:1" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> 复制代码
每行的item的outRect.left+outRect.right要相等，要不然会出现item的宽度不一致，因为item的宽度是 recyclerView的宽度除以每一行的spanCount然后在减去outRect.left和outRect.right，如果这一行每个item的outRect.left outRect.right之和不相等，就会出现item的宽度不一致了。
作者：用户8454164365033
链接：https://juejin.cn/post/7047765481977184287