Question

当我在TokenAuthorizeFilter中使用DI时，_User始终返回null。不仅仅是_User，这只是我遇到的一个例子。我尝试了不同的方法，但仍然无法正常工作。

我现在很困惑，请告诉我为什么。谢谢

public class BaseAuthorizeFilter : IAuthorizationFilter, IActionFilter
{
    public static ClaimsIdentity _User;
    public static IHttpContextAccessor _accessor;

    public BaseAuthorizeFilter(UserResolverService userService, IHttpContextAccessor accessor)
    {
        _User = userService.GetUser();
        _accessor = accessor;
    }
}
...

UserResolverService.cs

public class UserResolverService : IUserResolverService
{
    private readonly IHttpContextAccessor _context;

    public UserResolverService(IHttpContextAccessor context)
    {
        _context = context;
    }

    public ClaimsIdentity GetUser()
    {
        return _context.HttpContext.User.Identity as ClaimsIdentity;
        //await
    }
}

public interface IUserResolverService
{
    ClaimsIdentity GetUser();
}

TokenAuthorizeFilter.cs

public class TokenAuthorizeFilter : BaseAuthorizeFilter
{
    var identity = _User;
}

对不起，我没有在问题中提及任何内容。我正在从另一个类调用TokenAuthorizeFilter中的方法，因此我将其定义为静态。现在，我改变了编写方式，并从Microsoft网站上找到了答案。非常感谢。

https://docs.microsoft.com/en-us/aspnet/core/mvc/controllers/filters?view=aspnetcore-2.1#ifilterfactory-implemented-on-your-attribute

Answer 1

您的帖子中有多个问题。

您通过IUserResolverService注册了services.AddSingleton<IUserResolverService, UserResolverService>();，但是您注入了UserResolverService userService，
您不应将ClaimsIdentity _User定义为静态，而应将其隔离为请求

尝试如下更改：

    public class BaseAuthorizeFilter : IAuthorizationFilter, IActionFilter
{
    public ClaimsIdentity _User;
    public IHttpContextAccessor _accessor;

    public BaseAuthorizeFilter(IUserResolverService userService, IHttpContextAccessor accessor)
    {
        _User = userService.GetUser();
        _accessor = accessor;
    }

检查您的TokenAuthorizeFilter与以下代码之间的区别：

public class TokenAuthorizeFilter : BaseAuthorizeFilter
{
   public TokenAuthorizeFilter(IUserResolverService userService
       , IHttpContextAccessor accessor):base(userService, accessor)
  {
      var identity = _User;
  }
}

将TokenAuthorizeFilter注册为AddScoped

    services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
    services.AddSingleton<IUserResolverService, UserResolverService>();
    services.AddScoped<TokenAuthorizeFilter>();

在自定义过滤器.net Core中使用依赖注入始终为null

1 个答案: