feat: 优化

app/src/main/java/io/legado/app/help/AppConfig.kt

@@ -1,5 +1,6 @@
 package io.legado.app.help
 
+import android.annotation.SuppressLint
 import android.content.Context
 import android.content.pm.PackageManager
 import io.legado.app.App
@@ -122,7 +123,11 @@ object AppConfig {
         }
 
     var elevation: Int
-        get() = App.INSTANCE.getPrefInt("elevation", -1)
+        @SuppressLint("PrivateResource")
+        get() = App.INSTANCE.getPrefInt(
+            "elevation",
+            App.INSTANCE.resources.getDimension(R.dimen.design_appbar_elevation).toInt()
+        )
         set(value) {
             App.INSTANCE.putPrefInt("elevation", value)
         }

app/src/main/java/io/legado/app/ui/config/ThemeConfigFragment.kt

@@ -1,5 +1,6 @@
 package io.legado.app.ui.config
 
+import android.annotation.SuppressLint
 import android.content.SharedPreferences
 import android.os.Build
 import android.os.Bundle
@@ -115,6 +116,7 @@ class ThemeConfigFragment : PreferenceFragmentCompat(), SharedPreferences.OnShar
 
     }
 
+    @SuppressLint("PrivateResource")
     override fun onPreferenceTreeClick(preference: Preference?): Boolean {
         when (preference?.key) {
             "defaultTheme" -> alert(title = "切换默认主题") {