How do i reference a singleton instance i'm adding in the HostBuilder, as a part of a Scoped in-CodePudding

I may be barking up the wrong tree here, but, i have the following:

var host = new HostBuilder() 
    .ConfigureServices(services => 
    {
        services.AddSingleton<IHttpClientFactory>();
        services.AddScoped<IPaintMapper, PaintMapper(XXXXX, config)>();
    };

I want to pass the IHttpClientFactory into my Scoped "PaintMapper", which i will provide also a config for.

How would i do this? As the IHttpClientFactory and the "config" are both required to setup the scoped instance.

I've been at this refactor for a while and think my brain is not handling it particularly well, so my apologies if i'm missing something normal - but i don't see this done elsewhere, so i'm probably missing something.

CodePudding user response：

You can do like this

services.AddScoped<IPaintMapper, PaintMapper>(provider => {
    var config = provider.GetRequiredService<Config>();
    var httpFactory = provider.GetRequiredService<IHttpClientFactory>();
    // Do stuff with mapper
    return mapper;   
});

CodePudding user response：

The usual approach is to just register IHttpClientFactory and config type and resolve them from ctor. Scoped services can resolve singleton ones:

services.AddHttpClient(); // install Microsoft.Extensions.Http  nuget
services.AddXXX<PaintMapperSettings>();
services.AddScoped<IPaintMapper, PaintMapper>();

class PaintMapperSettings
{
    
}
class PaintMapper
{
    public PaintMapper(IHttpClientFactory factory, PaintMapperSettings settings)
    {
        
    }
}

For options to register and resolve settings - see the docs. Personally I tend to use the options pattern.