Reproduction Sample for Xamarin.Forms bug throwing a NullReferenceException when TraitCollectionDidChange Fires on RefreshView in Xamarin.Forms v4.6.0.529-pre3
- Download/Clone this repo
- In Visual Studio, open
TraitCollectionDidChangeRepro.sln - In Visual Studio, set the startup project to
TraitCollectionDidChangeRegression.iOS - Build & deploy
TraitCollectionDidChangeRegression.iOSto an iOS Simulator or Device - On the iOS device, wait for the app to launch
- Once the app has launched, in the macOS Apple Menu Bar, select Features > Toggle Appearance
- Confirm NullReferenceException is thrown
The current workaround is to downgrade from v4.6.0.529-pre3 to v4.6.0.494-pre2
The included code demonstrates the same Xamarin.Forms app working on v4.6.0.494-pre2:
- Download/Clone this repo
- In Visual Studio, open
TraitCollectionDidChangeRepro.sln - In Visual Studio, set the startup project to
TraitCollectionDidChangeWorking.iOS - Build & deploy
TraitCollectionDidChangeWorking.iOSto an iOS Simulator or Device - On the iOS device, wait for the app to launch
- Once the app has launched, in the macOS Apple Menu Bar, select Features > Toggle Appearance
- The Navigation Bar toggles between Light Mode and Dark Mode
=== Visual Studio Enterprise 2019 for Mac (Preview) ===
Version 8.6 Preview (8.6 build 3437) Installation UUID: 041ee3bd-ec0c-4084-9aa8-ccc56da6bd7a GTK+ 2.24.23 (Raleigh theme) Xamarin.Mac 6.18.0.21 (d16-6 / a87d63c06)
Package version: 610000095
=== Mono Framework MDK ===
Runtime: Mono 6.10.0.95 (2019-12/f2379f2d665) (64-bit) Package version: 610000095
=== Roslyn (Language Service) ===
3.6.0-2.20164.4+923b4bdbbd33307456464f4c90222a61af278972
=== NuGet ===
Version: 5.4.0.6315
=== .NET Core SDK ===
SDK: /usr/local/share/dotnet/sdk/3.1.200/Sdks SDK Versions: 3.1.200 3.1.102 3.0.101 2.1.803 MSBuild SDKs: /Library/Frameworks/Mono.framework/Versions/6.10.0/lib/mono/msbuild/Current/bin/Sdks
=== .NET Core Runtime ===
Runtime: /usr/local/share/dotnet/dotnet Runtime Versions: 5.0.0-preview.1.20120.5 3.1.2 3.1.1 3.1.0 3.0.1 2.1.16 2.1.15 2.1.14
=== Xamarin.Profiler ===
Version: 1.6.13.11 Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler
=== Updater ===
Version: 11
=== Apple Developer Tools ===
Xcode 11.4 (16134) Build 11E146
=== Xamarin.Mac ===
Version: 6.18.0.21 (Visual Studio Enterprise) Hash: a87d63c06 Branch: d16-6 Build date: 2020-03-02 11:17:04-0500
=== Xamarin.iOS ===
Version: 13.18.0.21 (Visual Studio Enterprise) Hash: a87d63c06 Branch: d16-6 Build date: 2020-03-02 11:17:05-0500
=== Xamarin Designer ===
Version: 16.6.0.267 Hash: fa27dc7ce Branch: remotes/origin/d16-6 Build date: 2020-03-19 20:26:14 UTC
=== Xamarin.Android ===
Version: 10.3.0.33 (Visual Studio Enterprise) Commit: xamarin-android/d16-6/e9fa8c4 Android SDK: /Users/bramin/Library/Developer/Xamarin/android-sdk-macosx Supported Android versions: 7.0 (API level 24)
SDK Tools Version: 26.1.1 SDK Platform Tools Version: 29.0.5 SDK Build Tools Version: 29.0.2
Build Information: Mono: d90665a Java.Interop: xamarin/java.interop/d16-6@2cab35c ProGuard: xamarin/proguard/master@905836d SQLite: xamarin/sqlite/3.31.1@49232bc Xamarin.Android Tools: xamarin/xamarin-android-tools/d16-6@bfb66f3
=== Microsoft Mobile OpenJDK ===
Java SDK: /Users/bramin/Library/Developer/Xamarin/jdk/microsoft_dist_openjdk_1.8.0.25 1.8.0-25 Android Designer EPL code available here: https://github.com/xamarin/AndroidDesigner.EPL
=== Android SDK Manager ===
Version: 16.6.0.46 Hash: f6bfa7b Branch: remotes/origin/d16-6 Build date: 2020-03-13 00:13:30 UTC
=== Android Device Manager ===
Version: 16.6.0.75 Hash: 4509c53 Branch: remotes/origin/d16-6 Build date: 2020-03-13 00:13:52 UTC
=== Xamarin Inspector ===
Version: 1.4.3 Hash: db27525 Branch: 1.4-release Build date: Mon, 09 Jul 2018 21:20:18 GMT Client compatibility: 1
=== Build Information ===
Release ID: 806003437 Git revision: b6e23a27c18a3e6f8eb620ff1814fb76b3f47921 Build date: 2020-03-20 11:39:40-04 Build branch: release-8.6 Xamarin extensions: b6e23a27c18a3e6f8eb620ff1814fb76b3f47921
=== Operating System ===
Mac OS X 10.15.4 Darwin 19.4.0 Darwin Kernel Version 19.4.0 Wed Mar 4 22:28:40 PST 2020 root:xnu-6153.101.6~15/RELEASE_X86_64 x86_64