Cautionary note. I had a working function and re-factored to put one of the function service dependencies in its own .net standard library. It stopped working.
If you get an error like
FunctionApp1: Method not found: 'Microsoft.Extensions.DependencyInjection.IServiceCollection Microsoft.Azure.Functions.Extensions.DependencyInjection.IFunctionsHostBuilder.get_Services()'.
Then you may be missing the crucial step I missed : setting the AzureFunctionsVersion from v2 to v3-preview in the project file. It worked as V2 as a single project function and only stopped working when I separated the injected dependency service into its own library. HTH.
Cautionary note. I had a working function and re-factored to put one of the function service dependencies in its own .net standard library. It stopped working.
If you get an error like
FunctionApp1: Method not found: 'Microsoft.Extensions.DependencyInjection.IServiceCollection Microsoft.Azure.Functions.Extensions.DependencyInjection.IFunctionsHostBuilder.get_Services()'.
Then you may be missing the crucial step I missed : setting the AzureFunctionsVersion from v2 to v3-preview in the project file. It worked as V2 as a single project function and only stopped working when I separated the injected dependency service into its own library. HTH.
Did this actually solve the problem for you? I am still getting the same error, even with v3-preview
Fixed it => the latest preview-release of the Microsoft.EntityFrameworkCore 3.1.0-preview3 seems to cause the problem