优化

app/src/main/java/io/legado/app/data/entities/rule/ExploreKind.kt

@@ -4,7 +4,7 @@ package io.legado.app.data.entities.rule
  * 发现分类
  */
 data class ExploreKind(
-    val title: String,
+    val title: String = "",
     val url: String? = null,
     val style: Style? = null
 ) {

app/src/main/java/io/legado/app/ui/book/source/debug/BookSourceDebugActivity.kt

@@ -128,7 +128,8 @@ class BookSourceDebugActivity : VMBaseActivity<ActivitySourceDebugBinding, BookS
                     return@launch
                 }
             }
-            exploreKinds?.map { it.title }?.let { exploreKindTitles ->
+            @Suppress("USELESS_ELVIS")
+            exploreKinds?.map { it.title ?: "" }?.let { exploreKindTitles ->
                 binding.textFx.onLongClick {
                     selector("选择发现", exploreKindTitles) { _, index ->
                         val explore = exploreKinds[index]