diff --git a/app/src/main/java/io/legado/app/help/config/ReadBookConfig.kt b/app/src/main/java/io/legado/app/help/config/ReadBookConfig.kt
index cf3c75b01..70111a54b 100644
--- a/app/src/main/java/io/legado/app/help/config/ReadBookConfig.kt
+++ b/app/src/main/java/io/legado/app/help/config/ReadBookConfig.kt
@@ -154,7 +154,15 @@ object ReadBookConfig {
                 appCtx.putPrefBoolean(PreferKey.shareLayout, value)
             }
         }
+
+    /**
+     * 两端对齐
+     */
     val textFullJustify get() = appCtx.getPrefBoolean(PreferKey.textFullJustify, true)
+
+    /**
+     * 底部对齐
+     */
     val textBottomJustify get() = appCtx.getPrefBoolean(PreferKey.textBottomJustify, true)
     var hideStatusBar = appCtx.getPrefBoolean(PreferKey.hideStatusBar)
     var hideNavigationBar = appCtx.getPrefBoolean(PreferKey.hideNavigationBar)
diff --git a/app/src/main/java/io/legado/app/ui/book/read/page/provider/ChapterProvider.kt b/app/src/main/java/io/legado/app/ui/book/read/page/provider/ChapterProvider.kt
index 6b948ac3c..fbb4167d6 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/page/provider/ChapterProvider.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/page/provider/ChapterProvider.kt
@@ -300,10 +300,11 @@ object ChapterProvider {
         srcList: LinkedList<String>? = null
     ): Pair<Int, Float> {
         var absStartX = x
-        val layout = if (ReadBookConfig.useZhLayout) ZhLayout(text, textPaint, visibleWidth)
-        else StaticLayout(
-            text, textPaint, visibleWidth, Layout.Alignment.ALIGN_NORMAL, 0f, 0f, true
-        )
+        val layout = if (ReadBookConfig.useZhLayout) {
+            ZhLayout(text, textPaint, visibleWidth)
+        } else {
+            StaticLayout(text, textPaint, visibleWidth, Layout.Alignment.ALIGN_NORMAL, 0f, 0f, true)
+        }
         var durY = when {
             //标题y轴居中
             isTitleWithNoContent && textPages.size == 1 -> {
@@ -375,7 +376,7 @@ object ChapterProvider {
                     } else {
                         0f
                     }
-                    addCharsToLineLast(
+                    addCharsToLineNatural(
                         book, absStartX, textLine, words.toStringArray(),
                         textPaint, startX, srcList
                     )
@@ -416,7 +417,7 @@ object ChapterProvider {
     ) {
         var x = 0f
         if (!ReadBookConfig.textFullJustify) {
-            addCharsToLineLast(book, absStartX, textLine, words, textPaint, x, srcList)
+            addCharsToLineNatural(book, absStartX, textLine, words, textPaint, x, srcList)
             return
         }
         val bodyIndent = ReadBookConfig.paragraphIndent
@@ -454,7 +455,7 @@ object ChapterProvider {
         srcList: LinkedList<String>?
     ) {
         if (!ReadBookConfig.textFullJustify) {
-            addCharsToLineLast(book, absStartX, textLine, words, textPaint, startX, srcList)
+            addCharsToLineNatural(book, absStartX, textLine, words, textPaint, startX, srcList)
             return
         }
         val gapCount: Int = words.lastIndex
@@ -470,9 +471,9 @@ object ChapterProvider {
     }
 
     /**
-     * 最后一行,自然排列
+     * 自然排列
      */
-    private suspend fun addCharsToLineLast(
+    private suspend fun addCharsToLineNatural(
         book: Book,
         absStartX: Int,
         textLine: TextLine,
diff --git a/app/src/main/java/io/legado/app/ui/book/read/page/provider/ZhLayout.kt b/app/src/main/java/io/legado/app/ui/book/read/page/provider/ZhLayout.kt
index 648392e83..c2aaa5a7d 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/page/provider/ZhLayout.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/page/provider/ZhLayout.kt
@@ -12,7 +12,7 @@ import kotlin.math.max
  * */
 @Suppress("MemberVisibilityCanBePrivate", "unused")
 class ZhLayout(
-    text: String,
+    text: CharSequence,
     textPaint: TextPaint,
     width: Int
 ) : Layout(text, textPaint, width, Alignment.ALIGN_NORMAL, 0f, 0f) {
diff --git a/app/src/main/java/io/legado/app/utils/StringExtensions.kt b/app/src/main/java/io/legado/app/utils/StringExtensions.kt
index 74d7eac7a..dc58912d9 100644
--- a/app/src/main/java/io/legado/app/utils/StringExtensions.kt
+++ b/app/src/main/java/io/legado/app/utils/StringExtensions.kt
@@ -8,6 +8,8 @@ import android.net.Uri
 import android.text.Editable
 import io.legado.app.constant.AppPattern.dataUriRegex
 import java.io.File
+import java.lang.Character.codePointCount
+import java.lang.Character.offsetByCodePoints
 import java.util.*
 
 fun String?.safeTrim() = if (this.isNullOrBlank()) null else this.trim()
@@ -100,12 +102,12 @@ fun String?.memorySize(): Int {
 /**
  * 将字符串拆分为单个字符,包含emoji
  */
-fun String.toStringArray(): Array<String> {
+fun CharSequence.toStringArray(): Array<String> {
     var codePointIndex = 0
     return try {
-        Array(codePointCount(0, length)) {
+        Array(codePointCount(this, 0, length)) {
             val start = codePointIndex
-            codePointIndex = offsetByCodePoints(start, 1)
+            codePointIndex = offsetByCodePoints(this, start, 1)
             substring(start, codePointIndex)
         }
     } catch (e: Exception) {