HttpRequestMessageExtensions not being found at run-time in Azure Function

Question

I\'ve got an Azure Function app that creates a precompiled DLL (so it uses normal .cs files, not the older .csx method, pre-VS2017). Previously, it was targeting .Net Framew

Answer 1

I had the same issue running my Azure Function locally and eventually tracked it down to conflicting System.Net.Http assemblies. I created my Azure function from a blank ASP.NET Web App and initially pulled down the System.Net.Http NuGet package to use within the project. I also pulled down the Microsoft.AspNet.WebApi.Client for use within the project. It did not matter which version of System.Net.Http I tried my project would compile but fail when the request was made.

Eventually, I removed packages I had downloaded, cleaned the build folder and added just the Microsoft.AspNet.WebApi.Client. I noticed that this automatically referenced the System.Net.Http on my machine for my version of the .NET Framework. (C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework). This compiled successfully and I was able to make requests to the function without any exceptions.