调用AddAuthorization是不明确的

有一些简单的政策一直在努力，直到今天，我很确定我没有做任何事情来打破它们。 在Startup.cs中，在ConfigureServices中，这是抛出错误的代码：

services.AddAuthorization(options => { options.AddPolicy("AboveUser", policy => policy.RequireRole("Admin", "Manager")); options.AddPolicy("IsAdmin", policy => policy.RequireRole("Admin")); options.AddPolicy("IsManager", policy => policy.RequireRole("Manager")); }); 

它给了我AddAuthorization函数的这个错误：

以下方法或属性之间的调用不明确：’Microsoft.Extensions.DependencyInjection.AuthorizationServiceCollectionExtensions.AddAuthorization（Microsoft.Extensions.DependencyInjection.IServiceCollection，System.Action）’和’Microsoft.Extensions.DependencyInjection.AuthorizationServiceCollectionExtensions.AddAuthorization（Microsoft.Extensions） .DependencyInjection.IServiceCollection，System.Action）’

我记不起最近对我的project.json或类似的东西进行了更改，但如果有帮助我会在这里引用它：

 { "dependencies": { "Microsoft.AspNetCore.Razor.Tools": { "version": "1.0.0-preview2-final", "type": "build" }, "Microsoft.EntityFrameworkCore.Tools": { "version": "1.0.0-preview2-final", "type": "build" }, "Microsoft.VisualStudio.Web.CodeGeneration.Tools": { "version": "1.0.0-preview2-final", "type": "build" }, "Microsoft.VisualStudio.Web.CodeGenerators.Mvc": { "version": "1.0.0-preview2-final", "type": "build" }, "BundlerMinifier.Core": "2.2.306", "Microsoft.ApplicationInsights.AspNetCore": "2.0.0", "Microsoft.AspNetCore.Authentication.Cookies": "1.1.0", "Microsoft.AspNetCore.Diagnostics": "1.1.0", "Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore": "1.1.0", "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.1.0", "Microsoft.AspNetCore.Mvc": "1.1.0", "Microsoft.AspNetCore.Routing": "1.1.0", "Microsoft.AspNetCore.Server.IISIntegration": "1.1.0", "Microsoft.AspNetCore.Server.Kestrel": "1.1.0", "Microsoft.AspNetCore.StaticFiles": "1.1.0", "Microsoft.EntityFrameworkCore.SqlServer": "1.1.0", "Microsoft.EntityFrameworkCore.SqlServer.Design": "1.1.0", "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.1.0", "Microsoft.Extensions.Configuration.Json": "1.1.0", "Microsoft.Extensions.Configuration.UserSecrets": "1.1.0", "Microsoft.Extensions.Logging": "1.1.0", "Microsoft.Extensions.Logging.Console": "1.1.0", "Microsoft.Extensions.Logging.Debug": "1.1.0", "Microsoft.Extensions.Options.ConfigurationExtensions": "1.1.0", "Microsoft.NETCore.App": "1.1.0", "Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.1.0", "Microsoft.EntityFrameworkCore": "1.1.0", "Microsoft.AspNet.Mvc.Core": "6.0.0-*", "Microsoft.Extensions.DependencyInjection.Abstractions": "1.1.0" }, "tools": { "Microsoft.AspNetCore.Razor.Tools": "1.0.0-preview2-final", "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final", "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final", "Microsoft.Extensions.SecretManager.Tools": "1.0.0-preview2-final", "Microsoft.VisualStudio.Web.CodeGeneration.Tools": { "version": "1.0.0-preview2-final", "imports": [ "portable-net45+win8" ] } }, "frameworks": { "netcoreapp1.0": { "imports": [ "dotnet5.6", "portable-net45+win8" ] } }, "buildOptions": { "emitEntryPoint": true, "preserveCompilationContext": true }, "runtimeOptions": { "configProperties": { "System.GC.Server": true } }, "runtimes": { "win7-x64": { } }, "publishOptions": { "include": [ "wwwroot", "**/*.cshtml", "appsettings.json", "web.config" ] }, "scripts": { "prepublish": [ "bower install", "dotnet bundle" ], "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% - -framework %publish:FullTargetFramework%" ] } } 

任何帮助将不胜感激

 "Microsoft.AspNet.Mvc.Core": "6.0.0-*", 

 "Microsoft.AspNetCore.Mvc.Core": "1.1.0",