How to set up strongly typed configuration in ASP.

2019-03-03 09:02发布

问题:

This article and this other article show how you can map your appsettings to a class in ASP.NET 5.

From the first link:

    public void ConfigureServices(IServiceCollection services)
    {
        services.Configure<AppSettings>(Configuration.GetConfigurationSection("AppSettings"));
        services.AddMvc();
    }

However, I'm not getting the Configure() method on services. So either I'm missing a package, or the API has changed. Which is it?

I'm using RC1. I believe the articles are based on beta 4.

回答1:

This example should give you what you need. I have this class:

public class UIOptions
{
    public UIOptions()
    { }

    public int DefaultPageSize_SiteList { get; set; } = 10;
    public int DefaultPageSize_CountryList { get; set; } = 10;
    public int DefaultPageSize_StateList { get; set; } = 10;
    public int DefaultPageSize_RoleList { get; set; } = 10;
    public int DefaultPageSize_RoleMemberList { get; set; } = 10;
    public int DefaultPageSize_UserList { get; set; } = 10;
    public int DefaultPageSize_LogView { get; set; } = 10;

}

If I want to override any of the default values I can add this in my appsettings.json:

"UIOptions": {
"DefaultPageSize_SiteList" : "5"
}

But if I'm not changing anything it doesn't matter if this exists in the appsettings.json file.

In startup I have this:

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

In a controller where I need the options injected I have a constructor dependency on

IOptions<UIOptions>

Note that I get my UIOptions instance from the .Value property of the IOptions

using Microsoft.Extensions.OptionsModel;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;

public class CoreDataController : Controller
{
    public CoreDataController(
        IOptions<UIOptions> uiOptionsAccessor
        )
    {

        uiOptions = uiOptionsAccessor.Value;
    }

    private UIOptions uiOptions;

}


回答2:

Make sure you're using the Microsoft.Extensions.DependencyInjection package. The package names were changes somewhere around beta8