我的 Xamarin.Forms 应用程序在 Android 上完美运行，但当我部署到 iOS（物理 iPhone 8）时，它不断出现故障。我在 AppDelegate 或第一页中设置了断点，但所有内容都因以下信息而中断：
2021-08-27 18:39:24.004 Xamarin.PreBuilt.iOS[4330:1030659] Xamarin.iOS: Successfully received USB connection from the IDE on port 10000, fd: 6
2021-08-27 18:39:24.007 Xamarin.PreBuilt.iOS[4330:1030659] Xamarin.iOS: Processing: 'start profiler: no'
2021-08-27 18:39:24.007 Xamarin.PreBuilt.iOS[4330:1030624] Xamarin.iOS: Profiler not loaded (disabled)
Loaded assembly: /private/var/containers/Bundle/Application/092BCD0C-2FC9-4F1B-A83E-29D87ACD245E/SHAPP.iOS.app/Xamarin.iOS.dll [External]
2021-08-27 18:39:24.334 Xamarin.PreBuilt.iOS[4330:1030624] Xamarin.iOS: Unable to locate assembly 'SHAPP' (culture: '')
2021-08-27 18:39:24.334 Xamarin.PreBuilt.iOS[4330:1030624] Xamarin.iOS: Unable to locate assembly 'SHAPP' (culture: '')
Loaded assembly: /private/var/mobile/Containers/Data/Application/6FE32CF0-AE4D-41A2-BBBA-EAD56133AA7E/Documents/SHAPP.iOS.content/Xamarin.Forms.Core.dll [External]
2021-08-27 18:39:24.404 Xamarin.PreBuilt.iOS[4330:1030624] Xamarin.iOS: Unable to locate assembly 'FFImageLoading' (culture: '')
2021-08-27 18:39:24.404 Xamarin.PreBuilt.iOS[4330:1030624] Xamarin.iOS: Unable to locate assembly 'FFImageLoading' (culture: '')
Loaded assembly: /private/var/mobile/Containers/Data/Application/6FE32CF0-AE4D-41A2-BBBA-EAD56133AA7E/Documents/SHAPP.iOS.content/FFImageLoading.Platform.dll [External]
....
[0:] Failed to force load assembly /var/mobile/Containers/Data/Application/6FE32CF0-AE4D-41A2-BBBA-EAD56133AA7E/Documents/SHAPP.iOS.content/Forms9Patch.dll. Type:Forms9Patch.PopupLayerEffect. Exception: 'You must call Xamarin.Forms.Forms.Init(); prior to using this property.'. Callstack: ' at Xamarin.Forms.Device.get_PlatformServices () [0x00007] in D:\a\1\s\Xamarin.Forms.Core\Device.cs:87
at Xamarin.Forms.Device.GetAssemblies () [0x00000] in D:\a\1\s\Xamarin.Forms.Core\Device.cs:245
at Xamarin.Forms.DependencyService.Initialize () [0x00021] in D:\a\1\s\Xamarin.Forms.Core\DependencyService.cs:103
at Xamarin.Forms.DependencyService.Get[T] (Xamarin.Forms.DependencyFetchTarget fetchTarget) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\DependencyService.cs:28
at Forms9Patch.Settings.ConfirmInitialization () [0x00008] in C:\Users\ben\Development\Xamarin\Forms9Patch\Forms9Patch\Forms9Patch\Models\Settings.cs:116
at Forms9Patch.PopupLayerEffect..cctor () [0x00000] in C:\Users\ben\Development\Xamarin\Forms9Patch\Forms9Patch\Forms9Patch\Effects\PopupLayerEffect.cs:19 '
...
[0:] An error occurred: 'Could not create an native instance of the type 'Airbnb.Lottie.LOTAnimationView': the native class hasn't been loaded.
It is possible to ignore this condition by setting ObjCRuntime.Class.ThrowOnInitFailure to false.'. Callstack: ' at Foundation.NSObject.InitializeObject (System.Boolean alloced) [0x0002e] in /Users/builder/azdo/_work/1/s/xamarin-macios/src/Foundation/NSObject2.cs:247
at Foundation.NSObject..ctor (Foundation.NSObjectFlag x) [0x0000d] in /Users/builder/azdo/_work/1/s/xamarin-macios/src/Foundation/NSObject2.cs:147
at UIKit.UIResponder..ctor (Foundation.NSObjectFlag t) [0x00000] in /Users/builder/azdo/_work/1/s/xamarin-macios/src/build/ios/native/UIKit/UIResponder.g.cs:74
at UIKit.UIView..ctor (Foundation.NSObjectFlag t) [0x00000] in
... --- 从先前抛出异常的位置开始的堆栈跟踪结束 ---
at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)
at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Users/builder/azdo/_work/1/s/xamarin-macios/src/UIKit/UIApplication.cs:86
at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0000e] in /Users/builder/azdo/_work/1/s/xamarin-macios/src/UIKit/UIApplication.cs:65
at SHAPP.iOS.Application.Main (System.String[] args) [0x00001] in C:\VisualCSharp\MyProjects\SHAPP\SHAPP.iOS\Main.cs:17
at (wrapper managed-to-native) System.Reflection.RuntimeMethodInfo.InternalInvoke(System.Reflection.RuntimeMethodInfo,object,object[],System.Exception&)
at System.Reflection.RuntimeMethodInfo.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x0006a] in /Library/Frameworks/Xamarin.iOS.framework/Versions/Current/src/Xamarin.iOS/mcs/class/corlib/System.Reflection/RuntimeMethodInfo.cs:395 '
Die App wurde beendet.
应用程序代理：
using Foundation;
using Lottie.Forms.Platforms.Ios;
using UIKit;
namespace SHAPP.iOS
{
// The UIApplicationDelegate for the application. This class is responsible for launching the
// User Interface of the application, as well as listening (and optionally responding) to
// application events from iOS.
[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
//
// This method is invoked when the application has loaded and is ready to run. In this
// method you should instantiate the window, load the UI into it and then make the window
// visible.
//
// You have 17 seconds to return from this method, or iOS will terminate your application.
//
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
global::Xamarin.Forms.Forms.Init();
Xamarin.Forms.Forms.Init();
Forms9Patch.iOS.Settings.Initialize(this);
FFImageLoading.Forms.Platform.CachedImageRenderer.Init();
ZXing.Net.Mobile.Forms.iOS.Platform.Init();
// ObjCRuntime.Class.ThrowOnInitFailure = false;
LoadApplication(new App());
//AnimationViewRenderer.Init();
return base.FinishedLaunching(app, options);
}
}
}
设置旧的 Lottie Init 没有帮助。我取消了 iOS 中的所有 NuGet Lottiefiles 并重新安装了它们，我清理了项目并重新启动了构建，同样的错误。唯一可行的办法就是完全取消 Lottieusage。
Lottie-XAML：
<lottie:AnimationView
Animation="14525-plumbers.json"
AutoPlay="True"
RepeatCount="3"
RepeatMode="Restart"
CacheComposition="True"
HeightRequest="500"
VerticalOptions="Start"
HorizontalOptions="Center"
IsVisible="true"
/>
如果我将其注释掉，一切都会正常。 LottieAnimationfile 位于我的资源文件夹 (BundledResource) 以及主文件夹中。
正如 Jason 提到的，您需要在 AppDelegate 中添加该行，如您在 此示例
中看到的那样但是您还有另一个错误，因为您可以在共享的 StackTrace 末尾阅读错误消息：
An error occurred: 'Could not create an native instance of the type 'Airbnb.Lottie.LOTAnimationView': the native class hasn't been loaded.
It is possible to ignore this condition by setting ObjCRuntime.Class.ThrowOnInitFailure to false.'. Callstack: ' at Foundation.NSObject.InitializeObject (System.Boolean alloced) [0x0002e] in /Users/builder/azdo/_work/1/s/xamarin-macios/src/Foundation/NSObject2.cs:247
at Foundation.NSObject..ctor (Foundation.NSObjectFlag x) [0x0000d] in /Users/builder/azdo/_work/1/s/xamarin-macios/src/Foundation/NSObject2.cs:147
您使用什么 Lottie 套餐？是这个吗？您使用的是最新版本吗？ 您必须确保将 iOS 版本的 Lottie 包添加到 iOS 项目中。