在Visual Studio 2013和2015中运行一段代码时，我得到了两个不同的结果。在Visual Studio 2015中，我得到了一个NullReference错误，而在2013年，它按照预期工作。此外，Visual Studio 2015运行在Windows 10上，而2013年则运行在Windows 8.1上。这段代码如下：
private static T FindParentOfType<T>(DependencyObject o)
{
dynamic parent = VisualTreeHelper.GetParent(o);
return parent.GetType().IsAssignableFrom(typeof(T)) ? parent : FindParentOfType<T>(parent);
}
代码的调用方式如下：
Grid RiskGrid = FindParentOfType<Grid>(ChampViewModelSel);
当检查 IsAssginableFrom 时，出现了 Nullreference 错误，因为在 VS2015 中找到的是 Canvas 而不是 VS2013 中希望找到的 Grid 。
堆栈跟踪
StackTrace " at Microsoft.CSharp.RuntimeBinder.SymbolTable.GetOriginalTypeParameterType(Type t)\r\n
at Microsoft.CSharp.RuntimeBinder.SymbolTable.AreTypeParametersEquivalent(Type t1, Type t2)\r\n
at Microsoft.CSharp.RuntimeBinder.SymbolTable.LoadMethodTypeParameter(MethodSymbol parent, Type t)\r\n
at Microsoft.CSharp.RuntimeBinder.SymbolTable.LoadSymbolsFromType(Type originalType)\r\n
at Microsoft.CSharp.RuntimeBinder.SymbolTable.AddMethodToSymbolTable(MemberInfo member, AggregateSymbol callingAggregate, MethodKindEnum kind)\r\n
at Microsoft.CSharp.RuntimeBinder.SymbolTable.AddNamesInInheritanceHierarchy(String name, BindingFlags flags, List 1 inheritance)\r\n
at Microsoft.CSharp.RuntimeBinder.SymbolTable.PopulateSymbolTableWithName(String name, IEnumerable 1 typeArguments, Type callingType)\r\n
at Microsoft.CSharp.RuntimeBinder.RuntimeBinder.PopulateSymbolTableWithPayloadInformation(DynamicMetaObjectBinder payload, Type callingType, ArgumentObject[] arguments)\r\n
at Microsoft.CSharp.RuntimeBinder.RuntimeBinder.BindCore(DynamicMetaObjectBinder payload, IEnumerable 1 parameters, DynamicMetaObject[] args, DynamicMetaObject& deferredBinding)\r\n
at Microsoft.CSharp.RuntimeBinder.RuntimeBinder.Bind(DynamicMetaObjectBinder payload, IEnumerable 1 parameters, DynamicMetaObject[] args, DynamicMetaObject& deferredBinding)\r\n
at Microsoft.CSharp.RuntimeBinder.BinderHelper.Bind(DynamicMetaObjectBinder action, RuntimeBinder binder, IEnumerable 1 args, IEnumerable 1 arginfos, DynamicMetaObject onBindingError)\r\n
at Microsoft.CSharp.RuntimeBinder.CSharpInvokeMemberBinder.FallbackInvokeMember(DynamicMetaObject target, DynamicMetaObject[] args, DynamicMetaObject errorSuggestion)\r\n
at System.Dynamic.DynamicMetaObject.BindInvokeMember(InvokeMemberBinder binder, DynamicMetaObject[] args)\r\n
at System.Dynamic.InvokeMemberBinder.Bind(DynamicMetaObject target, DynamicMetaObject[] args)\r\n
at System.Dynamic.DynamicMetaObjectBinder.Bind(Object[] args, ReadOnlyCollection 1 parameters, LabelTarget returnLabel)\r\n
at System.Runtime.CompilerServices.CallSiteBinder.BindCore[T](CallSite 1 site, Object[] args)\r\n
at System.Dynamic.UpdateDelegates.UpdateAndExecute2[T0,T1,TRet](CallSite site, T0 arg0, T1 arg1)\r\n
at BC_Game.ViewModel.ChampionViewModel.FindParentOfType[T](DependencyObject o)\r\n
at BC_Game.ViewModel.ChampionViewModel.ManStart(ManipulationStartedEventArgs e)" string
更新
在Win10上安装了VS2013，但问题仍然存在。在Win8.1上，VS2013可以正常工作。
更新
来自Visual Studio 2013 wp 8.1。
C:\Program Files (x86)\MSBuild\12.0\bin\Csc.exe /noconfig /nowarn:1701,1702,2008 /nostdlib+ /errorreport:prompt /warn:4 /define:DEBUG;TRACE /errorendlocation /preferreduilang:en-US /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\mscorlib.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\Microsoft.CSharp.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\mscorlib.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.Core.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.Net.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.Runtime.Serialization.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.ServiceModel.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.ServiceModel.Web.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.Windows.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.Xml.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.Xml.Linq.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETPortable\v4.0\Profile\Profile158\System.Xml.Serialization.dll" /debug+ /debug:full /filealign:512 /optimize- /out:obj\Debug\LibraryOfModels.dll /target:library /utf8output BuyMenuClass.cs CastleModel.cs ChampionModel.cs ChatDTO.cs CollectionCombiner.cs Country.cs CurrentUser.cs DecorationListItems.cs GameDTO.cs MapTransform.cs MarketplaceModel.cs MenuFirstPageModel.cs NotifyBase.cs Player.cs PopupColorPickerModel.cs PopupExtraInfoModel.cs PopUpModel.cs Properties\AssemblyInfo.cs RankingDTO.cs RankingModel.cs ShieldGearModel.cs UnitModel.cs UserDTO.cs WarCalculations.cs "C:\Users\Jonas\AppData\Local\Temp.NETPortable,Version=v4.0,Profile=Profile158.AssemblyAttributes.cs"来自VS 2015 Win 10
"C:\Program Files (x86)\MSBuild\14.0\bin\csc.exe" is a command to compile C# code. The long list of options and references following the command specify various settings for the compilation process, such as which .NET framework libraries to use and where to output the compiled code.我们能够看到这两个之间唯一的区别就是使用的.Net框架版本不同，其中一个是4.5.51650，而另一个则是4.6.01038。
更新：
看起来最新的win10电脑更新已经解决了这个问题。