如何在ASP.NET MVC中的角色中设置权限？

public class ApplicationRoleManager : RoleManager<IdentityRole>
{
    public ApplicationRoleManager(IRoleStore<IdentityRole, string> roleStore)
        : base(roleStore)
    {
    }

    public static ApplicationRoleManager Create(IdentityFactoryOptions<ApplicationRoleManager> options, IOwinContext context)
    {
        var roleStore = new RoleStore<IdentityRole>(context.Get<ApplicationDbContext>());
        return new ApplicationRoleManager(roleStore);
    }
}

public class ApplicationUserManager : UserManager<ApplicationUser>
{
    public ApplicationUserManager(IUserStore<ApplicationUser> store)
        : base(store)
    {
    }

    public static ApplicationUserManager Create(IdentityFactoryOptions<ApplicationUserManager> options, IOwinContext context)
    {
        var manager = new ApplicationUserManager(new UserStore<ApplicationUser>(context.Get<ApplicationDbContext>()));
        // 添加角色管理器
        manager.RoleManager = context.Get<ApplicationRoleManager>();
        return manager;
    }
}

public class CustomAuthorizeAttribute : AuthorizeAttribute
{
    protected override bool AuthorizeCore(HttpContextBase httpContext)
    {
        // 检查用户是否具有所需的角色
        return httpContext.User.IsInRole("Admin");
    }

    protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
    {
        // 如果用户没有所需的角色，则重定向到自定义的未授权页面
        filterContext.Result = new RedirectResult("~/Error/Unauthorized");
    }
}

[CustomAuthorize(Roles = "Admin")]
public ActionResult AdminOnlyAction()
{
    // 只有具有"Admin"角色的用户才能访问此操作方法
    return View();
}