在asp.net核心中将加载配置添加到注入依赖项中

Question

In my Asp.Net Core API, I have some repository classes I'm injecting by using the services.AddTransient method in my Startup.cs

services.AddTransient<IRepository, Repository>();

I'm also loading a section of my appsettings.json into a custom object in the Startup.cs

services.Configure<AppSettings>(Configuration.GetSection("AppSettings"));

My repository class needs to load the db connection string from the appsettings.json. Is there a way to inject these settings straight to the repository class? Or is it up to the constructor of the controller to pass the connection string to the repository class?

Answer 1

Yes, you can inject this directly to your repository.

    public MyRepository(IOptions<MyConfig> config)
    {
        var connString = config.Value.DbConnString;
    }

where MyConfig is a POCO object of your configuration and is getting added/registered in startup:

    public void ConfigureServices(IServiceCollection services)
    {
        ...
        services.Configure<MyConfig>(Configuration);
    }

The MyConfig can look something like this:

    public class MyConfig
    {
        public string DbConnString { get; set; }
    }

And the appsettings.json like this:

{
  "ApplicationName": "MyApp",
  "Version": "1.0.0",
  "DbConnString ": "my-conn-string"
}