如何替换自定义 appsettings.json 文件中的列表项？

Question

I have custom appsettings.json files for each environment, so appsettings.Dev.json, appsettings.Test.json, appsettings.Prod.json. In the main appsettings.json, I have the following code:

  "EmailSettings": {
    "Recipients": [
      "person@test.com"
    ]
  }

Then in the custom json file, I want to override this list, like this:

  "EmailSettings": {
    "Recipients": [
      "anotherperson@test.com"
    ]
  }

But instead, this gets appended like this:

  "EmailSettings": {
    "Recipients": [
      "person@test.com",
      "anotherperson@test.com"
    ]
  }

With all other types of settings, they get replaced, but for some reason, it seems that lists in custom settings files get appended instead. With .net, you used to have more granularity with the xslt to be able to determine whether you wanted to replace or append overridden settings. Any suggestions here?

SOLUTION (for me)

I did this, and it gets replaced in the custom json settings. Main appsettings.json:

  "EmailSettings": {
    "Recipients:0": "person@test.com"
  }

Then in the custom settings file:

  "EmailSettings": {
    "Recipients:0": "anotherperson@test.com"
  }

Thanks for the responses!

Answer 1

I utilized different appsettings files for environments (including Development )

So first make sure you have added the environment json file in your configuration:

config.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
.AddJsonFile($"appsettings.{EnvironmentName}.json", optional: true, reloadOnChange: true)

Then in my original appsettings.json it would be something like:

"EmailSettings": {
    "Recipients": []
}

and then for local development ( Development environment): appsettings.Development.json

"EmailSettings": {
    "Recipients": [
        "person@test.com"
    ]
}

and then for the other environment (lets call it Staging ): appsettings.Staging.json

"EmailSettings": {
    "Recipients": [
        "anotherperson@test.com"
    ]
}

Then, just make sure in your additional environments you have set ASPNETCORE_ENVIRONMENT in environment variables.

Answer 2

In the appsettings.Test.json use the following

"EmailSettings:Recipients:0" : "anotherperson@test.com"

The Configuration API is capable of maintaining hierarchical configuration data by flattening the hierarchical data with the use of a delimiter in the configuration keys.

You will need to define the Email Settings class like

   public class EmailSettings
    {
        public List<string> Recipients { get; set; }
    }

and wireup the DI to add the options in the Configure Method in Startup class

public void ConfigureServices(IServiceCollection services)
        {
            // add Options
            services.AddOptions();
            services.Configure<EmailSettings>(Configuration.GetSection("EmailSettings"));
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
        }