From efa9711e35f528245cdfb6c7028129c97ae10192 Mon Sep 17 00:00:00 2001
From: zhongwuzw <zhongwuzw@qq.com>
Date: Tue, 20 Aug 2024 10:44:41 -0700
Subject: [PATCH] Fixes Appearance user interface style when app run from
 background (#46021)

Summary:
Fixes https://github.com/facebook/react-native/issues/46015.

## Changelog:

[IOS] [FIXED] - Fixes Appearance user interface style when app run from background

Pull Request resolved: https://github.com/facebook/react-native/pull/46021

Test Plan: Demo in https://github.com/facebook/react-native/issues/46015.

Reviewed By: christophpurrer

Differential Revision: D61536857

Pulled By: cipolleschi

fbshipit-source-id: ee06cb25b5fc4fa72d646efe212738e54b9ef858
---
 packages/react-native/React/CoreModules/RCTAppearance.mm | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/packages/react-native/React/CoreModules/RCTAppearance.mm b/packages/react-native/React/CoreModules/RCTAppearance.mm
index 457a1d8b966..b5bcc313a82 100644
--- a/packages/react-native/React/CoreModules/RCTAppearance.mm
+++ b/packages/react-native/React/CoreModules/RCTAppearance.mm
@@ -70,8 +70,13 @@ NSString *RCTColorSchemePreference(UITraitCollection *traitCollection)
     return appearances[@(traitCollection.userInterfaceStyle)];
   }
 
+  if (!traitCollection) {
+    traitCollection = [UITraitCollection currentTraitCollection];
+  }
+
   UIUserInterfaceStyle systemStyle = sUseKeyWindowForSystemStyle ? RCTKeyWindow().traitCollection.userInterfaceStyle
                                                                  : traitCollection.userInterfaceStyle;
+
   return appearances[@(systemStyle)] ?: RCTAppearanceColorSchemeLight;
 }