c# - Web API 在 Controller 构造函数中读取 header 值

Question

是否可以在 Web API Controller 的构造函数中获取 header 信息？我想根据 header 值设置变量，但我不想为每种方法都这样做。我对自定义 header 值特别感兴趣，但此时我会接受授权值。我可以让它在 AuthorizationFilterAttribute 中工作，但我也需要它在 Controller 级别。

[PolicyAuthorize]
public class PoliciesController : ApiController
{
    public PoliciesController()
    {
        var x = HttpContext.Current;  //will be null in constructor
    }

    public HttpResponseMessage Get()
    {
        var x = HttpContext.Current;  //will be available but too late
    }
}

public class PolicyAuthorizeAttribute : AuthorizationFilterAttribute
{
    public override void OnAuthorization(HttpActionContext actionContext)
    {
        var authHeader = actionContext.Request.Headers.Authorization;  //can get at Authorization header here but no HTTPActionContext in controller
    }
}

Answer 1

以下是您可以考虑的一些选项...首选 1. 而不是 2.

1. 在当前请求消息的属性包 HttpRequestMessage.Properties 中存储额外的数据，并在 Controller 中有一个方便的属性， Controller 中的所有操作都可以访问该属性。

   [CustomAuthFilter]
   public class ValuesController : ApiController
   {
       public string Name
       {
           get
           {
               return Request.Properties["Name"].ToString();
           }
       }
   
       public string GetAll()
       {
           return this.Name;
       }
   }
   
   public class CustomAuthFilter : AuthorizationFilterAttribute
   {
       public override void OnAuthorization(HttpActionContext actionContext)
       {
           actionContext.Request.Properties["Name"] = "<your value from header>";
       }
   }
   

2. 您可以获得当前 Controller 的实例并设置属性值。示例:

   [CustomAuthFilter]
   public class ValuesController : ApiController
   {
       public string Name { get; set; }
   
       public string GetAll()
       {
           return this.Name;
       }
   }
   
   public class CustomAuthFilter : AuthorizationFilterAttribute
   {
       public override void OnAuthorization(HttpActionContext actionContext)
       {
           ValuesController valuesCntlr = actionContext.ControllerContext.Controller as ValuesController;
   
           if (valuesCntlr != null)
           {
               valuesCntlr.Name = "<your value from header>";
           }
       }
   }