feat: 优化代码

app/src/main/java/io/legado/app/base/adapter/CommonRecyclerAdapter.kt

@@ -293,6 +293,11 @@ abstract class CommonRecyclerAdapter<ITEM>(protected val context: Context) :
     fun getItem(position: Int): ITEM? =
         if (position in 0 until items.size) items[position] else null
 
+    fun getItemByLayoutPosition(position: Int): ITEM? {
+        val pos = position - getHeaderCount()
+        return if (pos in 0 until items.size) items[pos] else null
+    }
+
     fun getItems(): List<ITEM> = items
 
     protected open fun getItemViewType(item: ITEM, position: Int): Int {

app/src/main/java/io/legado/app/ui/book/read/config/BgTextConfigDialog.kt

@@ -155,7 +155,7 @@ class BgTextConfigDialog : DialogFragment() {
         override fun registerListener(holder: ItemViewHolder) {
             holder.itemView.apply {
                 this.onClick {
-                    getItem(holder.layoutPosition - getHeaderCount())?.let {
+                    getItemByLayoutPosition(holder.layoutPosition)?.let {
                         ReadBookConfig.durConfig.setBg(1, it)
                         ReadBookConfig.upBg()
                         postEvent(EventBus.UP_CONFIG, false)