Question

我正在学习EntityFramework Core。我刚刚完美。我正在添加migraitons并删除它们但是后来我需要在UI上工作几天然后我需要添加一些迁移但它没有工作。我尝试添加和删除（我已多次这样做）Microsoft.EntityFrameworkCore.Tools但它没有工作。我在包管理器控制台中添加命令＆＃34; add-migration someMigration＆＃34;在下面。我在不同的网站上搜索了近10天，但我无法理解发生的事情。提前完成。

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.TypeLoadException: Method 'Clone' in type            'Microsoft.EntityFrameworkCore.Infrastructure.Internal.SqlServerOptionsExtension' from assembly        'Microsoft.EntityFrameworkCore.SqlServer, Version=1.1.2.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' does not have an implementation.
   at      System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
   at   System.Reflection.RuntimeMethodInfo.FetchNonReturnParameters()
   at   System.Reflection.RuntimeMethodInfo.GetParameters()
   at   System.Diagnostics.StackTrace.ToString(TraceFormat traceFormat)
   at   System.Exception.GetStackTrace(Boolean needFileInfo)
   at   System.Exception.ToString(Boolean needFileLineInfo, Boolean needMessage)
   at     Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
   --- End of inner exception stack trace ---
   at    System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   at     System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at    System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, StackCrawlMark& stackMark)
   at    System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
   at    System.Activator.CreateInstance(String assemblyString, String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, Evidence securityInfo, StackCrawlMark& stackMark)
   at    System.Activator.CreateInstance(String assemblyName, String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
   at     System.AppDomain.CreateInstance(String assemblyName, String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
   at    System.AppDomain.CreateInstance(String assemblyName, String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
   at     Microsoft.EntityFrameworkCore.Tools.AppDomainOperationExecutor.Execute(String operationName, Object resultHandler, IDictionary arguments)
   at System.Dynamic.UpdateDelegates.UpdateAndExecuteVoid4[T0,T1,T2,T3](CallSite site, T0 arg0, T1 arg1, T2 arg2, T3 arg3)
   at    Microsoft.EntityFrameworkCore.Tools.OperationExecutorBase.InvokeOperationImpl(String operationName, IDictionary arguments)
   at     Microsoft.EntityFrameworkCore.Tools.OperationExecutorBase.AddMigration(String name, String outputDir, String contextType)
   at    Microsoft.EntityFrameworkCore.Tools.Commands.MigrationsAddCommand.Execute()
   at     Microsoft.DotNet.Cli.CommandLine.CommandLineApplication.Execute(String[] args)
   at     Microsoft.EntityFrameworkCore.Tools.Program.Main(String[] args)
Exception has been thrown by the target of an invocation.

System.Reflection.TargetInvocationException：调用目标抛出了异常。实体框架核心

0 个答案: