从启动类访问配置对象 [英] Access to Configuration object from Startup class

问题描述

我想从我的公司在ASP.NET vNext项目的许多控制器中访问Active Directory，并将域名插入到config.json文件中，以便可以从Configuration类访问它.我发现每次访问我的config.json时总是实例化一个新的Configuration对象很麻烦，是否有任何方法可以通过IConfiguration API访问初始化为Startup类的Configuration类?

I would like to access to the Active Directory from my company in many controllers from my ASP.NET vNext project, and I inserted the domain name into my config.json file, so I can access it from the Configuration class. I find it heavy to always instantiate a new Configuration object at every time I want to access to my config.json, is there any way through the IConfiguration API to access to the Configuration class initialized into the Startup class ?

推荐答案

如何执行此操作的示例:

An example of how you can do this:

假设您有一个config.json，如下所示:

Let's assume you have a config.json like below:

{
    "SomeSetting1": "some value here",
    "SomeSetting2": "some value here",
    "SomeSetting3": "some value here",
    "ActiveDirectory": {
        "DomainName": "DOMAIN-NAME-HERE"
    }
}

创建具有您的选项信息的POCO类型:

Create a POCO type having your option information:

public class ActiveDirectoryOptions
{
    public string DomainName { get; set; }
}

在Startup.cs中，配置服务时:

In Startup.cs, when configuring services:

services.Configure<ActiveDirectoryOptions>(optionsSetup =>
{
    //get from config.json file
    optionsSetup.DomainName = configuration.Get("ActiveDirectory:DomainName");
});

在所有想要获得此配置设置的控制器中，执行类似...的操作，此处这些选项由DI系统注入:

In all controllers which want to get this config setting, do something like...Here the options is injected by the DI system:

public class HomeController : Controller
{
    private readonly IOptions<ActiveDirectoryOptions> _activeDirectoryOptions;

    public HomeController(IOptions<ActiveDirectoryOptions> activeDirectoryOptions)
    {
        _activeDirectoryOptions = activeDirectoryOptions;
    }

    public IActionResult Index()
    {
        string domainName = _activeDirectoryOptions.Options.DomainName;

        ........
    }
}

---

回复评论:
我可以想到几种选择:

---

Responding to the comment:
There are couple of options that I can think of:

1. 您可以在操作中执行

1. From within the action, you can do

var options = HttpContext.RequestServices.GetRequiredService<IOptions<ActiveDirectoryOptions>>().Options;

您可以为用FromServicesAttribute装饰的动作设置一个参数.该属性将导致从DI中检索参数值. 示例:

You can have a parameter to the action which is decorated with FromServicesAttribute. This attribute will cause the parameter value to be retrieved from the DI. Example:

public IActionResult Index([FromServices] IOptions<ActiveDirectoryOptions> options)

相对于#1，我更喜欢#2，因为在进行单元测试时，它会为您提供所有相关部件的信息.

I prefer #2 over #1 as in case of unit testing it gives you information on all dependent pieces.

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