API 初始使用期间 ReactiveUI 性能下降

Question

我刚开始为我的 Xamarin Android 和 iOS 项目使用 ReactiveUI。我注意到我的 Android 使用 ReactiveUI 的片段最初需要很长时间才能加载。例如，在我的应用程序中第一次调用 ReactiveCommand.Create 时，大约需要 250 毫秒。第一次调用 OneWayBind、WhenAny、BindCommand 时类似的事情。但是，如果我再次重新实例化视图和视图模型，这些方法 return 几乎立即（< 3 毫秒）。

public ReactiveCommand<Unit, Unit> ButtonCommand { get; }

System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
sw.Start();

ButtonCommand = ReactiveCommand.Create(() => Console.WriteLine("test"));

long test = sw.ElapsedMilliseconds;
Console.WriteLine(test);

为了解决这个问题，我在启动画面期间随机调用主线程中的 ReactiveUI API。我是否错过了我在文档中错过的 ReactiveUI 初始化步骤？还有其他人有这个问题吗？这是 Android，我还没试过 iOS。

更新感谢格伦的回复，你是对的。我将尝试调查我的项目设置是否正确。视图模型位于 .NET Standard 2.0 项目中，该项目具有 ReactiveUI 和 Fody 包引用。我的 Android 项目和 Android 库有 ReactiveUI 和 RxUI.AndroidSupport。以下是调用 ReactiveCommand.Create 时的日志。不确定为什么它甚至正在探测 WinForm、WPF、XamForms...

06-30 17:39:39.178 I/mono-stdout(28083): XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - start
06-30 17:39:39.222 D/Mono    (28083): Loading reference 1 of System.Core.dll asmctx DEFAULT, looking for System, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
06-30 17:39:39.222 D/Mono    (28083): Assembly Ref addref System.Core[0x7c76e09880] -> System[0x7c76dbbf80]: 8
06-30 17:39:39.239 D/Mono    (28083): Loading reference 0 of /storage/emulated/0/Android/data/com.philips.CareTouch.B00/files/.__override__/Splat.dll asmctx DEFAULT, looking for mscorlib, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
06-30 17:39:39.239 D/Mono    (28083): Assembly Ref addref Splat[0x7cd15ab900] -> mscorlib[0x7cd15a1480]: 29
06-30 17:39:39.244 D/Mono    (28083): Loading reference 4 of /storage/emulated/0/Android/data/com.philips.CareTouch.B00/files/.__override__/Splat.dll asmctx DEFAULT, looking for System.Core, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
06-30 17:39:39.244 D/Mono    (28083): Assembly Ref addref Splat[0x7cd15ab900] -> System.Core[0x7c76e09880]: 6
06-30 17:39:39.284 D/Mono    (28083): Loading reference 3 of /storage/emulated/0/Android/data/com.philips.CareTouch.B00/files/.__override__/ReactiveUI.dll asmctx DEFAULT, looking for System.Core, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
06-30 17:39:39.284 D/Mono    (28083): Assembly Ref addref ReactiveUI[0x7cd15ab600] -> System.Core[0x7c76e09880]: 7
06-30 17:39:39.287 D/Mono    (28083): Loading reference 2 of /storage/emulated/0/Android/data/com.philips.CareTouch.B00/files/.__override__/Splat.dll asmctx DEFAULT, looking for System, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e
06-30 17:39:39.287 D/Mono    (28083): Assembly Ref addref Splat[0x7cd15ab900] -> System[0x7c76dbbf80]: 9
06-30 17:39:39.294 D/Mono    (28083): Loading reference 7 of /storage/emulated/0/Android/data/com.philips.CareTouch.B00/files/.__override__/ReactiveUI.dll asmctx DEFAULT, looking for Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065
06-30 17:39:39.294 D/Mono    (28083): Assembly Ref addref ReactiveUI[0x7cd15ab600] -> Mono.Android[0x7c76dbbd00]: 17
06-30 17:39:39.347 D/Mono    (28083): DllImport searching in: '__Internal' ('(null)').
06-30 17:39:39.347 D/Mono    (28083): Searching for 'java_interop_jnienv_call_long_method_a'.
06-30 17:39:39.347 D/Mono    (28083): Probing 'java_interop_jnienv_call_long_method_a'.
06-30 17:39:39.347 D/Mono    (28083): Found as 'java_interop_jnienv_call_long_method_a'.
06-30 17:39:39.360 D/Mono    (28083): Assembly Loader probing location: '/Users/builder/jenkins/workspace/xamarin-android-d16-1/xamarin-android/external/mono/sdks/out/android-arm64-v8a-release/lib/ReactiveUI.XamForms.dll'.
06-30 17:39:39.360 D/Mono    (28083): Assembly Loader probing location: '/Users/builder/jenkins/workspace/xamarin-android-d16-1/xamarin-android/external/mono/sdks/out/android-arm64-v8a-release/lib/ReactiveUI.XamForms.exe'.
06-30 17:39:39.366 D/Mono    (28083): Assembly Loader probing location: '/Users/builder/jenkins/workspace/xamarin-android-d16-1/xamarin-android/external/mono/sdks/out/android-arm64-v8a-release/lib/ReactiveUI.Winforms.dll'.
06-30 17:39:39.366 D/Mono    (28083): Assembly Loader probing location: '/Users/builder/jenkins/workspace/xamarin-android-d16-1/xamarin-android/external/mono/sdks/out/android-arm64-v8a-release/lib/ReactiveUI.Winforms.exe'.
06-30 17:39:39.367 D/Mono    (28083): Assembly Loader probing location: '/Users/builder/jenkins/workspace/xamarin-android-d16-1/xamarin-android/external/mono/sdks/out/android-arm64-v8a-release/lib/ReactiveUI.Wpf.dll'.
06-30 17:39:39.367 D/Mono    (28083): Assembly Loader probing location: '/Users/builder/jenkins/workspace/xamarin-android-d16-1/xamarin-android/external/mono/sdks/out/android-arm64-v8a-release/lib/ReactiveUI.Wpf.exe'.
06-30 17:39:39.368 D/Mono    (28083): Assembly Loader probing location: '/Users/builder/jenkins/workspace/xamarin-android-d16-1/xamarin-android/external/mono/sdks/out/android-arm64-v8a-release/lib/ReactiveUI.Uno.dll'.
06-30 17:39:39.368 D/Mono    (28083): Assembly Loader probing location: '/Users/builder/jenkins/workspace/xamarin-android-d16-1/xamarin-android/external/mono/sdks/out/android-arm64-v8a-release/lib/ReactiveUI.Uno.exe'.
06-30 17:39:39.489 I/mono-stdout(28083): XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - end
06-30 17:39:39.490 I/mono-stdout(28083): Elapsed 323

Answer 1

目前 RxUI 加载依赖 DLL 的方式是使用以下 class.

它有一个硬编码字符串列表，与我们拥有的 NuGet 包的 DLL 相匹配。然后它将尝试加载列表中列出的 DLL，然后如果找到，运行 IWantsToRegisterStuff 接口包含在 class.

中

我相信你的速度变慢是因为这个 DLL 注册。

作为此工作的一部分，计划很快就会替换 task 计划是为了让您在 DLL 包的命名空间中针对 RxApp 实例调用 Init 方法。这项工作将出现在 ReactiveUI 11 中。

API 初始使用期间 ReactiveUI 性能下降

ReactiveUI slow performance during initial use of the API

xamarin.android

reactive-programming

reactiveui