Question

在迁移之后，我的XamarinForm项目使用共享.net starddard项目而不是pcl（以下链接https://blog.xamarin.com/building-xamarin-forms-apps-net-standard/）

当我右键单击共享项目（.net stardard proj）使用Prism ViewModel使用Prism模板包创建Xamarin.Forms ContentPage时出现此错误：

项目系统遇到错误。你调用的对象是空的。诊断日志已写入以下位置：“C：\ Users \ toumir \ AppData \ Local \ Temp \ VsProjectFault_7c3ce3c8-085f-4531-99cf-85d9a8b8ceee.failure.txt”。

日志文件内容

04-09-2017 09:05:10
Recoverable
System.NullReferenceException: Object reference not set to an instance of an object.
   at Prism.VisualStudio.Wizards.CreateViewModelForViewWizard.RunFinished()
   at Microsoft.VisualStudio.TemplateWizard.Wizard.Execute(Object application, Int32 hwndOwner, Object[]& ContextParams, Object[]& CustomParams, wizardResult& retval)
   at System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo)
   at Microsoft.VisualStudio.ErrorHandler.ThrowOnFailure(Int32 hr, Int32[] expectedHRFailure)
   at Microsoft.VisualStudio.ProjectSystem.VS.Implementation.Package.ProjectNode.RunWizard(SimpleHierarchyNode parentNode, String itemName, String wizardToRun, IntPtr dlgOwner)
   at Microsoft.VisualStudio.ProjectSystem.VS.Implementation.Package.ProjectNode.<AddItemWithSpecificAsync>d__602.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.ProjectSystem.VS.Implementation.Package.ProjectNode.<>c__DisplayClass468_0.<<AddItem>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.VisualStudio.Threading.JoinableTask.CompleteOnCurrentThread()
   at Microsoft.VisualStudio.Threading.JoinableTask`1.CompleteOnCurrentThread()
   at Microsoft.VisualStudio.Threading.JoinableTaskFactory.Run[T](Func`1 asyncMethod, JoinableTaskCreationOptions creationOptions)
   at Microsoft.VisualStudio.ProjectSystem.ProjectMultiThreadedService.ExecuteSynchronously[T](Func`1 asyncAction)
   at Microsoft.VisualStudio.ProjectSystem.VS.Implementation.Package.ProjectNode.<>c__DisplayClass559_0.<HrInvoke>b__0()
   at Microsoft.VisualStudio.ProjectSystem.VS.HResult.Invoke(Func`1 action, IServiceProvider vsShellServiceProvider, IProjectFaultHandlerService projectFaultHandlerService, UnconfiguredProject project)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.VisualStudio.ProjectSystem.CommonProjectSystemTools.Rethrow(Exception ex)
   at Microsoft.VisualStudio.ProjectSystem.ProjectErrorReporting.<>c__DisplayClass6_0.<SubmitErrorReport>b__0()
   at Microsoft.VisualStudio.ProjectSystem.ExceptionFilter.<>c__DisplayClass2_0.<Guard>b__0()
   at GuardMethodClass.GuardMethod(Func`1 , Func`2 , Func`2 )

以及显示此消息的另一个消息框：

“对象引用未设置为对象的实例。”

仅供参考：

使用PCL项目时没有问题
我的App类派生自PrismApplication

任何人都可以指导我们吗？提前谢谢

Answer 1

Prism Template Pack目前尚未正式支持.NET Standard项目格式。 Xamarin不附带任何.NET Standard兼容项目模板，Xamarin本身不是.NET Standard。当Xamarin更新为.NET Standard时，Prism模板包将随之而来。

Prism Template Pack - 在.net标准分片项目

1 个答案: