HttpContext.Current 使用 IAuthenticationFilter 时为空

Question

我正在使用 ng-file-upload 上传文件并遇到一些异常问题，因为使用 IAuthenticationFilter 时 HttpContext.Current 为空。当我在 WebApiConfig.

中评论身份验证过滤器时，一切正常

要测试的控制器

    [HttpPost]
    public IHttpActionResult Upload()
    {
        var current = HttpContext.Current;
        if (current == null)
        {
            return Content(HttpStatusCode.BadRequest, Logger.Error("HttpContext.Current is null"));
        }            

        if (current.Request != null && current.Request.Files != null)
        {
            var file = current.Request.Files.Count > 0 ? current.Request.Files[0] : null;
            if (file != null)
            {
                file.SaveAs(@"C:\Temp\test.csv");
            }
        }
        return Content(HttpStatusCode.BadRequest, Logger.Error("Should not reach here"));
    }

IAuthenticationFilter

public class KeyAuthentication : Attribute, IAuthenticationFilter
{
    // we only want to apply our authentication filter once on a controller or action method so return false:
    public bool AllowMultiple
    {
        get { return false; }
    }

    // Authenticate the user by apiKey
    public async Task AuthenticateAsync(HttpAuthenticationContext context, CancellationToken cancellationToken)
    {            
        HttpRequestMessage request = context.Request;

        string apiKey = ExtractApiKey(request);
        bool IsValidCustomer = await ValidateKey(apiKey);
        if (IsValidCustomer)
        {
            var currentPrincipal = new GenericPrincipal(new GenericIdentity(apiKey), null);
            context.Principal = principal;                
        }
        else
        {
             context.ErrorResult = new ErrorMessageResult("Missing API Key");
        }
    }

    // We don't want to add challange as I am using keys authenticaiton
    public Task ChallengeAsync(HttpAuthenticationChallengeContext context, CancellationToken cancellationToken)
    {  
        return Task.FromResult(0);
    }
}

提取API密钥

public static string ExtractApiKey(HttpRequestMessage request)
{
    if (!request.Headers.TryGetValues("x-api-key", out IEnumerable<string> keys))
return string.Empty;

    return keys.First();
}

Answer 1

解决方案是将 "targetFramework=4.5" 包含在 web.config 中，正如@Alfredo 评论的那样，更多细节在

中