RecyclerView线性布局&网格布局的上下左右间距封装kotlin版

先上用法： 线性布局代码设置：
recyclerView.addItemDecoration(Decoration.decoration(5, 5, 5,5))

网格布局代码设置：

recyclerView.addItemDecoration(Decoration.GridDecoration(3, 10, true))

Decoration（可直接用  也可根据自己需求自行修改~~~~）

import java.util.*


object Decoration {
    
    fun LinearDecoration(top: Int, bottom: Int, left: Int, right: Int): RecyclerViewSpacesItemDecoration {
   val stringIntegerHashMap = HashMap()
 //top间距
  stringIntegerHashMap[RecyclerViewSpacesItemDecoration.TOP_DECORATION] = top
//底部间距
  stringIntegerHashMap[RecyclerViewSpacesItemDecoration.BOTTOM_DECORATION] = bottom 
//左间距
  stringIntegerHashMap[RecyclerViewSpacesItemDecoration.LEFT_DECORATION] = left 
//右间距
  stringIntegerHashMap[RecyclerViewSpacesItemDecoration.RIGHT_DECORATION] = right    
  return RecyclerViewSpacesItemDecoration(stringIntegerHashMap)
    }

  

    
    fun GridDecoration(spanCount: Int, spacing: Int, includeEdge: Boolean): RecyclerViewGridDecoration {
        return RecyclerViewGridDecoration(spanCount, spacing, includeEdge)
    }
}

RecyclerViewSpacesItemDecoration(线性布局间隔设置)

import android.graphics.Rect
import android.view.View
import androidx.recyclerview.widget.RecyclerView
import androidx.recyclerview.widget.RecyclerView.ItemDecoration
import java.util.*

class RecyclerViewSpacesItemDecoration internal constructor(private val mSpaceValueMap: HashMap) : ItemDecoration() {
    override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
        if (mSpaceValueMap[TOP_DECORATION] != null) outRect.top = mSpaceValueMap[TOP_DECORATION]!!
        if (mSpaceValueMap[LEFT_DECORATION] != null) outRect.left = mSpaceValueMap[LEFT_DECORATION]!!
        if (mSpaceValueMap[RIGHT_DECORATION] != null) outRect.right = mSpaceValueMap[RIGHT_DECORATION]!!
        if (mSpaceValueMap[BOTTOM_DECORATION] != null) outRect.bottom = mSpaceValueMap[BOTTOM_DECORATION]!!
    }

    companion object {
        const val TOP_DECORATION = "top_decoration"
        const val BOTTOM_DECORATION = "bottom_decoration"
        const val LEFT_DECORATION = "left_decoration"
        const val RIGHT_DECORATION = "right_decoration"
    }

}

RecyclerViewGridDecoration(网格布局间隔设置)

import android.graphics.Rect
import android.view.View
import androidx.recyclerview.widget.RecyclerView
import androidx.recyclerview.widget.RecyclerView.ItemDecoration

class RecyclerViewGridDecoration internal constructor(private val spanCount: Int, private val spacing: Int, private val includeEdge: Boolean) : ItemDecoration() {
    override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
        // item position
        val position = parent.getChildAdapterPosition(view)
        // item column
        val column = position % spanCount
        if (includeEdge) {
            // spacing - column * ((1f / spanCount) * spacing)
            outRect.left = spacing - column * spacing / spanCount
            // (column + 1) * ((1f / spanCount) * spacing)
            outRect.right = (column + 1) * spacing / spanCount
            // top edge
            if (position < spanCount) {
                outRect.top = spacing
            }
            // item bottom
            outRect.bottom = spacing
        } else {
            // column * ((1f / spanCount) * spacing)
            outRect.left = column * spacing / spanCount
            // spacing - (column + 1) * ((1f /    spanCount) * spacing)
            outRect.right = spacing - (column + 1) * spacing / spanCount
            if (position >= spanCount) {
                // item top
                outRect.top = spacing
            }
        }
    }

}