Q:

.NET Standard Extension Libary for asp.net mvc 5's HtmlHelpr and asp.net core mvc's IHtmlHelper

My Question:
I hope create a .NET Standard Extension Libary  for asp.net mvc 5's HtmlHelpr and asp.net core mvc's IHtmlHelper.
Is it Possible to create a mini .NET Standard Class Libary without install System.Web.Mvc and Microsoft.AspNetCore.Mvc nuget package,and support all of them?,below demo is my test code.
My Test Demo:

Not install System.Web.Mvc and Microsoft.AspNetCore.Mvc nuget
Hope Using partial to avoid class conflicts 

namespace Microsoft.AspNetCore.Mvc.Rendering
{
    public partial interface IHtmlHelper{}
}

namespace System.Web.Mvc
{
    public partial class HtmlHelper { }
}

namespace TestExtension
{
    public static class TestExtension
    {
        public static void TestDemo(this IHtmlHelper htmlHelper) { }
        public static void TestDemo(this HtmlHelper htmlHelper) { }
    }
}

Error Message
When i add lib dll to asp.net mvc project get this error.

Compiler Error Message: CS0433: The type 'HtmlHelper' exists in both 'xxx.dll' and 'xxx.DLL'

A:

add batch="false" in the compilation tag of web.config file 
    web.config file:

<configuration …>
  <system.web>
    <compilation … batch=″false″/>

the problem is that APS uses the application references and folder structure to compile the app
if the batch property is set to false, APS will compile each folder into a separate assembly 
it's like using a full namespace qualifier for each single folder and avoid dll conflicts 

