ConfigureServices(IServiceCollection services) 中的模糊调用 services.AddOptions()

Question

在ConfigureServices(IServiceCollection services)中添加services.AddOptions()后出现如下错误：

CS0121  
The call is ambiguous between the following methods or properties: Microsoft.Extensions.DependencyInjection.OptionsServiceCollectionExtensions.AddOptions(Microsoft.Extensions.DependencyInjection.IServiceCollection) and Microsoft.Extensions.DependencyInjection.OptionsServiceCollectionExtensions.AddOptions(Microsoft.Extensions.DependencyInjection.IServiceCollection)'

代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;

...

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddOptions();
    ...
}

这特别奇怪，因为在相同的“方法或属性”之间存在歧义

Answer 1

根据this question 的反馈，我发现我在project.lock.json 中有一个对"EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final" 的引用，而"EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final" 本身就有对"Microsoft.Extensions.OptionsModel": "1.0.0-rc1-final" 的引用

重点是只引用"Microsoft.Extensions.Options": "1.0.0-rc2-final"，并删除所有OptionsModel。