如果用户使用 Google 登录，ASP.NET Core Identity 2.0 SignoutAsync 不会注销用户

我已设置并运行 Asp.net Core Identity 版本 2.0。我发现_signinManager.SignoutAsync用户登录 Google 后不会注销用户。当我返回登录方法时，它仅显示用户已登录，其声明对象仍然完好无损。

代码非常简单，如下所示

[AllowAnonymous]
public ActionResult TestGoogle()
{
    var redirectUrl = Url.Action(nameof(ExternalCallback), "Account", new { ReturnUrl = "" });
    var properties = _signInManager.ConfigureExternalAuthenticationProperties("Google", redirectUrl);
    return Challenge(properties, "Google");
}


public async Task<IActionResult> LogOff()
{
    await _signInManager.SignOutAsync();
    return RedirectToAction(nameof(HomeController.Index), "Home");
}

问题是你的RedirectToAction覆盖到 Identity Server 结束会话 URL 的重定向SignOutAsync issues.

As for SignOutAsync，过时的是Authentication部分——从 ASP.NET Core 2.0 开始，它是直接扩展HttpContext itself.

（对于相同的注销问题给出了相同的解释here https://github.com/aspnet/Security/issues/313#issuecomment-120668602由微软的Haok开发。）

编辑：解决方案是在AuthenticationProperties对象与最终SignOutAsync:

// in some controller/handler, notice the "bare" Task return value
public async Task LogoutAction()
{
    // SomeOtherPage is where we redirect to after signout
    await MyCustomSignOut("/SomeOtherPage");
}

// probably in some utility service
public async Task MyCustomSignOut(string redirectUri)
{
    // inject the HttpContextAccessor to get "context"
    await context.SignOutAsync("Cookies");
    var prop = new AuthenticationProperties()
    {
        RedirectUri = redirectUri
    };
    // after signout this will redirect to your provided target
    await context.SignOutAsync("oidc", prop);
}