Web API 2令牌过期/拒绝

Question

我正在使用基于web api 2令牌的身份验证，本地存储，以及我编写的Angular应用程序。感谢Taiseer Joudeh撰写的文章。一切都工作得很好，除了在一小时左右之后，用户被Web api [授权]拒绝访问，使用与首次登录时相同的令牌。令牌仍然存在于本地存储中。我正在使用默认的14天超时。令牌在哪里可能超时/过期？这是我正在使用的ConfigureAuth函数：

public partial class Startup
{
    public static OAuthAuthorizationServerOptions OAuthOptions { get; private set; }
    public static string PublicClientId { get; private set; }

    // For more information on configuring authentication, please visit http://go.microsoft.com/fwlink/?LinkId=301864

    public void ConfigureAuth(IAppBuilder app)
    {
        // Configure the db context and user manager to use a single instance per request
        app.CreatePerOwinContext(ApplicationDbContext.Create);
        app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);

        // Enable the application to use a cookie to store information for the signed in user
        // and to use a cookie to temporarily store information about a user logging in with a third party login provider
        app.UseCookieAuthentication(new CookieAuthenticationOptions());
        app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);

        // Configure the application for OAuth based flow
        PublicClientId = "self";
        OAuthOptions = new OAuthAuthorizationServerOptions
        {
            TokenEndpointPath = new PathString("/Token"),
            Provider = new ApplicationOAuthProvider(PublicClientId),
            AuthorizeEndpointPath = new PathString("/api/Account/ExternalLogin"),
            AccessTokenExpireTimeSpan = TimeSpan.FromDays(14),
            AllowInsecureHttp = true
        };

        // Enable the application to use bearer tokens to authenticate users
        app.UseOAuthBearerTokens(OAuthOptions);

    }
}