android - 已解决：使用 ItemDecorator 添加间距后的 Grid RecyclerView 空白

Question

我有一个 3 列网格回收视图，当我使用自定义项目装饰在项目之间添加空间时，回收器视图中的一些项目会在它们上获得空白，如图所示。

装饰者

class GridRecyclerItemDecorator(private val numberOfColumns: Int, private val rowSpacingDP: Float = 0f, private val columnSpacingDP: Float = 0f, private val edgeSpacingVerticalDP: Float = 0f, private val edgeSpacingHorizontalDP: Float = 0f) : RecyclerView.ItemDecoration() {

    override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
        val position = parent.getChildAdapterPosition(view)
        val numberOfRows = (parent.adapter?.itemCount?:-1)/numberOfColumns
        val column = position % numberOfColumns
        val row = position / numberOfColumns
        val context = view.context
        ///horizontal
        when(column){
            0 -> {
                outRect.left = convertDpToPixel(edgeSpacingVerticalDP,context)
                outRect.right = convertDpToPixel(columnSpacingDP/2, context)
            }
            numberOfColumns-1 -> {
                outRect.left = convertDpToPixel(columnSpacingDP/2, context)
                outRect.right = convertDpToPixel(edgeSpacingVerticalDP, context)
            }
            else -> {
                outRect.left = convertDpToPixel(columnSpacingDP/2, context)
                outRect.right = convertDpToPixel(columnSpacingDP/2, context)
            }
        }
        //vertical
        when(row){
            0  -> {
                outRect.top = convertDpToPixel(edgeSpacingHorizontalDP,context)
                outRect.bottom = convertDpToPixel(rowSpacingDP/2, context)
            }
            numberOfRows -> {
                outRect.top = convertDpToPixel(rowSpacingDP/2, context)
                outRect.bottom = convertDpToPixel(edgeSpacingHorizontalDP, context)
            }
            else -> {
                outRect.top = convertDpToPixel(rowSpacingDP/2, context)
                outRect.bottom = convertDpToPixel(rowSpacingDP/2, context)
            }
        }
    }
    fun convertDpToPixel(dp: Float, context: Context?): Int {
        return if (context != null) {
            val resources = context.resources
            val metrics = resources.displayMetrics
            (dp * (metrics.densityDpi.toFloat() / DisplayMetrics.DENSITY_DEFAULT)).roundToInt()
        } else {
            val metrics = Resources.getSystem().displayMetrics
            (dp * (metrics.densityDpi.toFloat() / DisplayMetrics.DENSITY_DEFAULT)).roundToInt()
        }
    }
}

项目布局

<com.google.android.material.card.MaterialCardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    app:cardCornerRadius="5dp"
    android:layout_height="wrap_content">
    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <ImageView
            android:id="@+id/ivHomeCategoryImage"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:scaleType="fitXY"
            android:contentDescription="categories"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintDimensionRatio="1:1"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

    </androidx.constraintlayout.widget.ConstraintLayout>

</com.google.android.material.card.MaterialCardView>

回收站设置

binding.rvShopCategoriesList.apply {
                    adapter = homeCategoryAdapter
                    addItemDecoration(
                        GridRecyclerItemDecorator(
                            3,
                            8f,
                            8f,
                            8f,
                            8f
                        )
                    )
                }

我从我身边检查了我所知道的一切，但我仍然无法弄清楚这是什么原因。提前致谢

编辑：我能够通过在 ViewHolder 布局文件中进行某些更改来解决此问题。问题实际上与布局文件有关

标签： androidxmlkotlinandroid-recyclerviewgrid-layout