From 6bb1cef1bae09b9b2bec06ae808e71db16d2ecde Mon Sep 17 00:00:00 2001
From: Kyle <kyle201817146@gmail.com>
Date: Sat, 7 Nov 2026 16:01:26 +0800
Subject: [PATCH] fix: keep visionOS hosting backgrounds transparent

Fixes #1251
---
 .../Hosting/UIKit/View/UIHostingView.swift    |  6 ++++++
 ...IHostingControllerCompatibilityTests.swift | 21 +++++++++++++++++++
 2 files changed, 27 insertions(+)
 create mode 100644 Tests/OpenSwiftUICompatibilityTests/Integration/Hosting/UIKit/UIHostingControllerCompatibilityTests.swift

diff --git a/Sources/OpenSwiftUI/Integration/Hosting/UIKit/View/UIHostingView.swift b/Sources/OpenSwiftUI/Integration/Hosting/UIKit/View/UIHostingView.swift
index 6a1e680a6..cc03a5395 100644
--- a/Sources/OpenSwiftUI/Integration/Hosting/UIKit/View/UIHostingView.swift
+++ b/Sources/OpenSwiftUI/Integration/Hosting/UIKit/View/UIHostingView.swift
@@ -386,6 +386,12 @@ open class _UIHostingView<Content>: UIView, XcodeViewDebugDataProvider where Con
         if wantsTransparentBackground {
             super.backgroundColor = nil
         } else {
+            #if os(visionOS)
+            if traitCollection.userInterfaceIdiom == .vision {
+                super.backgroundColor = nil
+                return
+            }
+            #endif
             setBackground(.systemBackground)
         }
     }
diff --git a/Tests/OpenSwiftUICompatibilityTests/Integration/Hosting/UIKit/UIHostingControllerCompatibilityTests.swift b/Tests/OpenSwiftUICompatibilityTests/Integration/Hosting/UIKit/UIHostingControllerCompatibilityTests.swift
new file mode 100644
index 000000000..235871cb2
--- /dev/null
+++ b/Tests/OpenSwiftUICompatibilityTests/Integration/Hosting/UIKit/UIHostingControllerCompatibilityTests.swift
@@ -0,0 +1,21 @@
+//
+//  UIHostingControllerCompatibilityTests.swift
+//  OpenSwiftUICompatibilityTests
+
+#if os(visionOS)
+import Testing
+import UIKit
+
+@MainActor
+struct UIHostingControllerCompatibilityTests {
+    @Test(arguments: [UIUserInterfaceStyle.light, .dark])
+    func visionBackgroundIsTransparent(style: UIUserInterfaceStyle) {
+        let controller = UIHostingController(rootView: EmptyView())
+        controller.overrideUserInterfaceStyle = style
+        controller.loadViewIfNeeded()
+
+        #expect(controller.view.traitCollection.userInterfaceIdiom == .vision)
+        #expect(controller.view.backgroundColor == nil)
+    }
+}
+#endif