diff --git a/app/src/main/java/io/legado/app/constant/PreferKey.kt b/app/src/main/java/io/legado/app/constant/PreferKey.kt
index 11480d669..c52c79c38 100644
--- a/app/src/main/java/io/legado/app/constant/PreferKey.kt
+++ b/app/src/main/java/io/legado/app/constant/PreferKey.kt
@@ -3,6 +3,6 @@ package io.legado.app.constant
 object PreferKey {
 
     const val downloadPath = "downloadPath"
-
-
+    const val hideStatusBar = "hideStatusBar"
+    const val hideNavigationBar = "hideNavigationBar"
 }
\ No newline at end of file
diff --git a/app/src/main/java/io/legado/app/ui/book/read/Help.kt b/app/src/main/java/io/legado/app/ui/book/read/Help.kt
index 1ff72d7dc..f522df279 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/Help.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/Help.kt
@@ -5,6 +5,7 @@ import android.view.View
 import android.view.View.NO_ID
 import android.view.ViewGroup
 import io.legado.app.App
+import io.legado.app.constant.PreferKey
 import io.legado.app.help.ReadBookConfig
 import io.legado.app.lib.theme.ATH
 import io.legado.app.lib.theme.ThemeStore
@@ -21,12 +22,12 @@ object Help {
                 or View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                 or View.SYSTEM_UI_FLAG_IMMERSIVE
                 or View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY)
-        val hideNavigationBar = App.INSTANCE.getPrefBoolean("hideNavigationBar")
+        val hideNavigationBar = App.INSTANCE.getPrefBoolean(PreferKey.hideNavigationBar)
         if (hideNavigationBar) {
             flag = flag or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
         }
         if (toolBarHide) {
-            if (App.INSTANCE.getPrefBoolean("hideStatusBar")) {
+            if (App.INSTANCE.getPrefBoolean(PreferKey.hideStatusBar)) {
                 flag = flag or View.SYSTEM_UI_FLAG_FULLSCREEN
             }
             if (hideNavigationBar) {
diff --git a/app/src/main/java/io/legado/app/ui/book/read/ReadMenu.kt b/app/src/main/java/io/legado/app/ui/book/read/ReadMenu.kt
index 0aa08497c..4504f1dee 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/ReadMenu.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/ReadMenu.kt
@@ -11,6 +11,7 @@ import androidx.core.view.isVisible
 import io.legado.app.App
 import io.legado.app.R
 import io.legado.app.constant.Bus
+import io.legado.app.constant.PreferKey
 import io.legado.app.lib.theme.accentColor
 import io.legado.app.lib.theme.buttonDisabledColor
 import io.legado.app.utils.*
@@ -197,7 +198,7 @@ class ReadMenu : FrameLayout {
                 vw_menu_bg.onClick { runMenuOut() }
                 vwNavigationBar.layoutParams = vwNavigationBar.layoutParams.apply {
                     height =
-                        if (context.getPrefBoolean("hideNavigationBar")
+                        if (context.getPrefBoolean(PreferKey.hideStatusBar)
                             && Help.isNavigationBarExist(activity)
                         ) context.getNavigationBarHeight()
                         else 0
diff --git a/app/src/main/java/io/legado/app/ui/book/read/config/MoreConfigDialog.kt b/app/src/main/java/io/legado/app/ui/book/read/config/MoreConfigDialog.kt
index 4a869a1ed..1175f3293 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/config/MoreConfigDialog.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/config/MoreConfigDialog.kt
@@ -12,6 +12,7 @@ import androidx.fragment.app.DialogFragment
 import androidx.preference.PreferenceFragmentCompat
 import io.legado.app.R
 import io.legado.app.constant.Bus
+import io.legado.app.constant.PreferKey
 import io.legado.app.lib.theme.ATH
 import io.legado.app.ui.book.read.Help
 import io.legado.app.utils.postEvent
@@ -91,8 +92,8 @@ class MoreConfigDialog : DialogFragment() {
             key: String?
         ) {
             when (key) {
-                "hideStatusBar" -> postEvent(Bus.UP_CONFIG, true)
-                "hideNavigationBar" -> postEvent(Bus.UP_CONFIG, true)
+                PreferKey.hideStatusBar -> postEvent(Bus.UP_CONFIG, true)
+                PreferKey.hideNavigationBar -> postEvent(Bus.UP_CONFIG, true)
             }
         }
 
diff --git a/app/src/main/java/io/legado/app/ui/widget/page/ContentView.kt b/app/src/main/java/io/legado/app/ui/widget/page/ContentView.kt
index 228e6f2e9..15f3c5127 100644
--- a/app/src/main/java/io/legado/app/ui/widget/page/ContentView.kt
+++ b/app/src/main/java/io/legado/app/ui/widget/page/ContentView.kt
@@ -10,6 +10,7 @@ import android.widget.ImageView
 import androidx.appcompat.widget.AppCompatImageView
 import io.legado.app.R
 import io.legado.app.constant.AppConst.TIME_FORMAT
+import io.legado.app.constant.PreferKey
 import io.legado.app.help.ReadBookConfig
 import io.legado.app.utils.*
 import kotlinx.android.synthetic.main.view_book_page.view.*
@@ -58,7 +59,7 @@ class ContentView : FrameLayout {
 
     fun upStyle() {
         ReadBookConfig.getConfig().apply {
-            val pt = if (context.getPrefBoolean("hideStatusBar", false)) {
+            val pt = if (context.getPrefBoolean(PreferKey.hideStatusBar, false)) {
                 top_bar.visible()
                 0
             } else {