先上图：
开发环境：
vs2017 preview 15.3+MySql.Data.EntityFrameworkCore 7.0.7-m61
报错内容：
发生了 System.TypeLoadException
HResult=0x80131522
Message=Method 'Clone' in type 'MySQL.Data.EntityFrameworkCore.Infraestructure.Internal.MySQLOptionsExtension' from assembly 'MySql.Data.EntityFrameworkCore, Version=7.0.7.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d' does not have an implementation.
Source=<无法计算异常源>
StackTrace:
at MySQL.Data.EntityFrameworkCore.Extensions.MySQLDbContextOptionsExtensions.UseMySQL(DbContextOptionsBuilder optionsBuilder, String connectionString, Action`1 MySQLOptionsAction)
at testproj.MemberPoint.Startup.<ConfigureServices>b__4_0(DbContextOptionsBuilder options) in D: estproj estprojSVNCommonFile runkNetCoreBusiness estproj.MemberPointStartup.cs:line 28
at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.<>c__DisplayClass0_0`1.<AddDbContext>b__0(IServiceProvider p, DbContextOptionsBuilder b)
at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.DbContextOptionsFactory[TContext](IServiceProvider applicationServiceProvider, Action`2 optionsAction)
at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.<>c__DisplayClass5_0`1.<AddCoreServices>b__0(IServiceProvider p)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactoryService(FactoryService factoryService, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitSingleton(SingletonCallSite singletonCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass17_0.<RealizeService>b__0(ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
at Microsoft.Extensions.Internal.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, Boolean isDefaultParameterRequired)
at Microsoft.AspNetCore.Mvc.Controllers.ControllerActivatorProvider.<>c__DisplayClass5_0.<CreateActivator>b__0(ControllerContext controllerContext)
at Microsoft.AspNetCore.Mvc.Controllers.ControllerFactoryProvider.<>c__DisplayClass5_0.<CreateControllerFactory>g__CreateController0(ControllerContext controllerContext)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeInnerFilterAsync>d__14.MoveNext()
经过各种查找，在这里找到了答案：https://blogs.msdn.microsoft.com/dotnet/2017/05/12/announcing-ef-core-2-0-preview-1/
注意这段话：
If you are using a third party database provider, then check to see if they have released an update that depends on 2.0.0-preview1-final. If they have, then just upgrade to the new version. If not, then you will not be able to upgrade since version 2.0 contains several breaking changes and 1.* providers are not expected to work with it.
所以答案是：没有答案。坐等MySQL.Data.EntityFrameworkCore更新吧。