Xamarin.Forms iOS mTouch 错误
Xamarin.Forms iOS mTouch Error
我正在 ESRI ArcGIS Runtime（Xamarin.Forms [共享]）开发应用程序。我在 Visual Studio 中使用默认的 ArcGIS 模板。当我 运行 IOS 的应用程序时，它 运行 成功，但每当我放大 4-5 倍时，应用程序 returns 我会出现以下错误，并且我添加了 xamarin 日志文件。我认为这不是关于 Esri ArcGIS Runtime，而是关于 Xamarin iOS Touch。我该如何解决？
Visual Studio 2015 输出中的错误：
2017-02-23 14:43:37.330 UniversalApp1[19079:218799]
Unhandled Exception:
System.NullReferenceException: Object reference not set to an instance of an object
at System.Net.Http.NSUrlSessionHandler+NSUrlSessionHandlerDelegate.DidReceiveData (Foundation.NSUrlSession session, Foundation.NSUrlSessionDataTask dataTask, Foundation.NSData data) [0x00008] in /Users/builder/data/lanes/3985/35d1ccd0/source/xamarin-macios/src/Foundation/NSUrlSessionHandler.cs:267
2017-02-23 14:43:37.337 UniversalApp1[19079:218799] Unhandled managed exception:
Object reference not set to an instance of an object (System.NullReferenceException)
at System.Net.Http.NSUrlSessionHandler+NSUrlSessionHandlerDelegate.DidReceiveData (Foundation.NSUrlSession session, Foundation.NSUrlSessionDataTask dataTask, Foundation.NSData data) [0x00008] in /Users/builder/data/lanes/3985/35d1ccd0/source/xamarin-macios/src/Foundation/NSUrlSessionHandler.cs:267
2017-02-23 14:43:37.338 UniversalApp1[19079:218799] critical: Stacktrace:
2017-02-23 14:43:37.338 UniversalApp1[19079:218799] critical:
Native stacktrace:
2017-02-23 14:43:37.382 UniversalApp1[19079:218799] critical: 0 UniversalApp1 0x0000000107b34dfd mono_handle_native_sigsegv + 253
2017-02-23 14:43:37.382 UniversalApp1[19079:218799] critical: 1 libsystem_platform.dylib 0x0000000111427bba _sigtramp + 26
2017-02-23 14:43:37.382 UniversalApp1[19079:218799] critical: 2 libsystem_kernel.dylib 0x00000001113eb430 libsystem_kernel.dylib + 1072
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical: 3 libsystem_c.dylib 0x000000011117efd7 abort + 129
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical: 4 UniversalApp1 0x0000000107ccc61f xamarin_unhandled_exception_handler + 47
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical: 5 UniversalApp1 0x0000000107b965fb mono_invoke_unhandled_exception_hook + 139
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical: 6 UniversalApp1 0x0000000107b3464f mono_handle_exception_internal + 5135
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical: 7 UniversalApp1 0x00000001
07b33238 mono_handle_exception + 24
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical: 8 UniversalApp1 0x0000000107aa9e0b altstack_handle_and_restore + 59
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical: 9 ??? 0x0000000121bac5b8 0x0 + 4860855736
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical: 10 UniversalApp1 0x0000000107b45387 mono_jit_runtime_invoke + 2247
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical: 11 UniversalApp1 0x0000000107bfa018 do_runtime_invoke + 88
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical: 12 UniversalApp1 0x0000000107bf9f90 mono_runtime_invoke + 208
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical: 13 UniversalApp1 0x0000000107cd15c5 xamarin_invoke_trampoline + 5589
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical: 14 UniversalApp1
0x0000000107cd917d xamarin_arch_trampoline + 189
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical: 15 UniversalApp1 0x0000000107cda531 xamarin_x86_64_common_trampoline + 110
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical: 16 CFNetwork 0x000000010f9ec88c __67-[NSURLSession delegate_dataTask:didReceiveData:completionHandler:]_block_invoke.242 + 38
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical: 17 Foundation 0x00000001098149ad __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 7
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical: 18 Foundation 0x000000010981468f -[NSBlockOperation main] + 101
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical: 19 Foundation 0x0000000109812d8c -[__NSOperationInternal _start:] + 672
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical: 20 Foundation
0x000000010980eccf __NSOQSchedule_f + 201
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical: 21 libdispatch.dylib 0x000000011108d12e _dispatch_client_callout + 8
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical: 22 libdispatch.dylib 0x00000001110724cf _dispatch_queue_serial_drain + 1018
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical: 23 libdispatch.dylib 0x0000000111072c9f _dispatch_queue_invoke + 1118
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical: 24 libdispatch.dylib 0x00000001110749dc _dispatch_root_queue_drain + 506
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical: 25 libdispatch.dylib 0x0000000111074782 _dispatch_worker_thread3 + 113
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical: 26 libsystem_pthread.dylib 0x0000000111439712 _pthread_wqthread + 1299
2017-02-23 14:43:37.389 UniversalApp1[19079:218799] critical: 2
7 libsystem_pthread.dylib 0x00000001114391ed start_wqthread + 13
2017-02-23 14:43:37.389 UniversalApp1[19079:218799] critical:
=================================================================
Got a SIGABRT while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================
The app has been terminated.
Launch failed. The app 'UniversalApp1.iOS' could not be launched on 'iPhone SE iOS 10.2'. Error: An error occurred while executing MTouch. Please check the logs for more details.
The app has been terminated.
Xamarin 日志中的这一部分
Xamarin.Messaging.Client.MessagingClient Error: 0 : [2017-02-23 14:43:39.9721] An error occured on the receiver while executing a post for topic xvs/idb/4.2.2.11/launch-app and client vs4120Sinan
Xamarin.Messaging.Exceptions.MessagingRemoteException: An error occured on client IDB42211 while executing a reply for topic xvs/idb/4.2.2.11/launch-app ---> Xamarin.Messaging.Exceptions.MonotouchException: An error occurred while executing MTouch
at Xamarin.Messaging.IDB.MTouch+<RunAsync>d__8.MoveNext () [0x0024a] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.MTouch+<RunAsync>d__7.MoveNext () [0x0007b] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.MTouch+<LaunchAsync>d__5.MoveNext () [0x000bd] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.Handlers.LaunchAppMessageHandler+<RunMTouchAsync>d__17.MoveNext () [0x00150] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.Handlers.LaunchAppMessageHandler+<ExecuteOnSimulatorAsync>d__13.MoveNext () [0x00086] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.Handlers.LaunchAppMessageHandler+<ExecuteAsync>d__12.MoveNext () [0x00092] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in <f712f98eb8e445c8918edaf595bbe465>:0
at Xamarin.Messaging.Client.RequestHandler`2+<HandleAsync>d__5[TMessage,TResult].MoveNext () [0x0011a] in <3ff57b845ff7490198f5f40dfdc63104>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in <f712f98eb8e445c8918edaf595bbe465>:0
at Xamarin.Messaging.Client.MessageHandlerManager+<>c__DisplayClass17_0`2+<<RegisterHandlerAsync>b__1>d[TMessage,TResult].MoveNext () [0x000b3] in <3ff57b845ff7490198f5f40dfdc63104>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in <f712f98eb8e445c8918edaf595bbe465>:0
at Xamarin.Messaging.Client.MessagingClient+<ReplyAsync>d__34`2[TRequest,TResponse].MoveNext () [0x000cf] in <3ff57b845ff7490198f5f40dfdc63104>:0
--- End of inner exception stack trace ---
at Xamarin.Messaging.Client.MessagingClient.<PostAsync>d__23`2.MoveNext()
- Visual Studio 2015社区（版本：14.0.25431.01更新3）
- Xamarin 4.2.0（Xamarin.Android7.0 – Xamarin.iOS10.2）
- ArcGIS 运行时 100 .Net SDK
提前致谢，
思南
此错误是由于 Xamarin 的 Cycle 9 版本中的行为更改所致。我们已经记录了 Xamarin 的问题（参见 here）。在根本问题得到解决之前，可以通过继续使用或降级到最新的 Cycle 8 版本来避免它。
编辑 - 此问题已在 Xamarin 的 Xcode 8.3 更新到 Cycle 9，SR0 版本（即 Xamarin iOS 10.6）中得到修复。它也在 Xamarin 的最新版本 (15.1) 中得到修复。
-富有
ArcGIS Runtime 团队
我正在 ESRI ArcGIS Runtime（Xamarin.Forms [共享]）开发应用程序。我在 Visual Studio 中使用默认的 ArcGIS 模板。当我 运行 IOS 的应用程序时，它 运行 成功，但每当我放大 4-5 倍时，应用程序 returns 我会出现以下错误，并且我添加了 xamarin 日志文件。我认为这不是关于 Esri ArcGIS Runtime，而是关于 Xamarin iOS Touch。我该如何解决？
Visual Studio 2015 输出中的错误：
2017-02-23 14:43:37.330 UniversalApp1[19079:218799]
Unhandled Exception:
System.NullReferenceException: Object reference not set to an instance of an object
at System.Net.Http.NSUrlSessionHandler+NSUrlSessionHandlerDelegate.DidReceiveData (Foundation.NSUrlSession session, Foundation.NSUrlSessionDataTask dataTask, Foundation.NSData data) [0x00008] in /Users/builder/data/lanes/3985/35d1ccd0/source/xamarin-macios/src/Foundation/NSUrlSessionHandler.cs:267
2017-02-23 14:43:37.337 UniversalApp1[19079:218799] Unhandled managed exception:
Object reference not set to an instance of an object (System.NullReferenceException)
at System.Net.Http.NSUrlSessionHandler+NSUrlSessionHandlerDelegate.DidReceiveData (Foundation.NSUrlSession session, Foundation.NSUrlSessionDataTask dataTask, Foundation.NSData data) [0x00008] in /Users/builder/data/lanes/3985/35d1ccd0/source/xamarin-macios/src/Foundation/NSUrlSessionHandler.cs:267
2017-02-23 14:43:37.338 UniversalApp1[19079:218799] critical: Stacktrace:
2017-02-23 14:43:37.338 UniversalApp1[19079:218799] critical:
Native stacktrace:
2017-02-23 14:43:37.382 UniversalApp1[19079:218799] critical: 0 UniversalApp1 0x0000000107b34dfd mono_handle_native_sigsegv + 253
2017-02-23 14:43:37.382 UniversalApp1[19079:218799] critical: 1 libsystem_platform.dylib 0x0000000111427bba _sigtramp + 26
2017-02-23 14:43:37.382 UniversalApp1[19079:218799] critical: 2 libsystem_kernel.dylib 0x00000001113eb430 libsystem_kernel.dylib + 1072
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical: 3 libsystem_c.dylib 0x000000011117efd7 abort + 129
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical: 4 UniversalApp1 0x0000000107ccc61f xamarin_unhandled_exception_handler + 47
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical: 5 UniversalApp1 0x0000000107b965fb mono_invoke_unhandled_exception_hook + 139
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical: 6 UniversalApp1 0x0000000107b3464f mono_handle_exception_internal + 5135
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical: 7 UniversalApp1 0x00000001
07b33238 mono_handle_exception + 24
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical: 8 UniversalApp1 0x0000000107aa9e0b altstack_handle_and_restore + 59
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical: 9 ??? 0x0000000121bac5b8 0x0 + 4860855736
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical: 10 UniversalApp1 0x0000000107b45387 mono_jit_runtime_invoke + 2247
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical: 11 UniversalApp1 0x0000000107bfa018 do_runtime_invoke + 88
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical: 12 UniversalApp1 0x0000000107bf9f90 mono_runtime_invoke + 208
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical: 13 UniversalApp1 0x0000000107cd15c5 xamarin_invoke_trampoline + 5589
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical: 14 UniversalApp1
0x0000000107cd917d xamarin_arch_trampoline + 189
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical: 15 UniversalApp1 0x0000000107cda531 xamarin_x86_64_common_trampoline + 110
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical: 16 CFNetwork 0x000000010f9ec88c __67-[NSURLSession delegate_dataTask:didReceiveData:completionHandler:]_block_invoke.242 + 38
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical: 17 Foundation 0x00000001098149ad __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 7
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical: 18 Foundation 0x000000010981468f -[NSBlockOperation main] + 101
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical: 19 Foundation 0x0000000109812d8c -[__NSOperationInternal _start:] + 672
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical: 20 Foundation
0x000000010980eccf __NSOQSchedule_f + 201
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical: 21 libdispatch.dylib 0x000000011108d12e _dispatch_client_callout + 8
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical: 22 libdispatch.dylib 0x00000001110724cf _dispatch_queue_serial_drain + 1018
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical: 23 libdispatch.dylib 0x0000000111072c9f _dispatch_queue_invoke + 1118
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical: 24 libdispatch.dylib 0x00000001110749dc _dispatch_root_queue_drain + 506
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical: 25 libdispatch.dylib 0x0000000111074782 _dispatch_worker_thread3 + 113
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical: 26 libsystem_pthread.dylib 0x0000000111439712 _pthread_wqthread + 1299
2017-02-23 14:43:37.389 UniversalApp1[19079:218799] critical: 2
7 libsystem_pthread.dylib 0x00000001114391ed start_wqthread + 13
2017-02-23 14:43:37.389 UniversalApp1[19079:218799] critical:
=================================================================
Got a SIGABRT while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================
The app has been terminated.
Launch failed. The app 'UniversalApp1.iOS' could not be launched on 'iPhone SE iOS 10.2'. Error: An error occurred while executing MTouch. Please check the logs for more details.
The app has been terminated.
Xamarin 日志中的这一部分
Xamarin.Messaging.Client.MessagingClient Error: 0 : [2017-02-23 14:43:39.9721] An error occured on the receiver while executing a post for topic xvs/idb/4.2.2.11/launch-app and client vs4120Sinan
Xamarin.Messaging.Exceptions.MessagingRemoteException: An error occured on client IDB42211 while executing a reply for topic xvs/idb/4.2.2.11/launch-app ---> Xamarin.Messaging.Exceptions.MonotouchException: An error occurred while executing MTouch
at Xamarin.Messaging.IDB.MTouch+<RunAsync>d__8.MoveNext () [0x0024a] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.MTouch+<RunAsync>d__7.MoveNext () [0x0007b] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.MTouch+<LaunchAsync>d__5.MoveNext () [0x000bd] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.Handlers.LaunchAppMessageHandler+<RunMTouchAsync>d__17.MoveNext () [0x00150] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.Handlers.LaunchAppMessageHandler+<ExecuteOnSimulatorAsync>d__13.MoveNext () [0x00086] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
at Xamarin.Messaging.IDB.Handlers.LaunchAppMessageHandler+<ExecuteAsync>d__12.MoveNext () [0x00092] in <b3b99d4df65f4615ba6dd9add880a191>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in <f712f98eb8e445c8918edaf595bbe465>:0
at Xamarin.Messaging.Client.RequestHandler`2+<HandleAsync>d__5[TMessage,TResult].MoveNext () [0x0011a] in <3ff57b845ff7490198f5f40dfdc63104>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in <f712f98eb8e445c8918edaf595bbe465>:0
at Xamarin.Messaging.Client.MessageHandlerManager+<>c__DisplayClass17_0`2+<<RegisterHandlerAsync>b__1>d[TMessage,TResult].MoveNext () [0x000b3] in <3ff57b845ff7490198f5f40dfdc63104>:0
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in <f712f98eb8e445c8918edaf595bbe465>:0
at Xamarin.Messaging.Client.MessagingClient+<ReplyAsync>d__34`2[TRequest,TResponse].MoveNext () [0x000cf] in <3ff57b845ff7490198f5f40dfdc63104>:0
--- End of inner exception stack trace ---
at Xamarin.Messaging.Client.MessagingClient.<PostAsync>d__23`2.MoveNext()
- Visual Studio 2015社区（版本：14.0.25431.01更新3）
- Xamarin 4.2.0（Xamarin.Android7.0 – Xamarin.iOS10.2）
- ArcGIS 运行时 100 .Net SDK
提前致谢， 思南
此错误是由于 Xamarin 的 Cycle 9 版本中的行为更改所致。我们已经记录了 Xamarin 的问题（参见 here）。在根本问题得到解决之前，可以通过继续使用或降级到最新的 Cycle 8 版本来避免它。
编辑 - 此问题已在 Xamarin 的 Xcode 8.3 更新到 Cycle 9，SR0 版本（即 Xamarin iOS 10.6）中得到修复。它也在 Xamarin 的最新版本 (15.1) 中得到修复。
-富有
ArcGIS Runtime 团队