diff --git a/app/src/main/java/io/legado/app/ui/book/read/ReadBookActivity.kt b/app/src/main/java/io/legado/app/ui/book/read/ReadBookActivity.kt
index fdc95233d..6a143f542 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/ReadBookActivity.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/ReadBookActivity.kt
@@ -203,6 +203,9 @@ class ReadBookActivity : VMBaseActivity<ReadBookViewModel>(R.layout.activity_boo
         return super.dispatchKeyEvent(event)
     }
 
+    /**
+     * 按键事件
+     */
     override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
         when (keyCode) {
             KeyEvent.KEYCODE_VOLUME_UP -> {