我在 Session["accesstoken"] 中设置从 facebook 检索的 accesstoken。当我尝试检索它时,我遇到了 nullreferenceexception。
为什么?
在我开始使用 AddAdditionalPermissions 方法之前它确实有效,但我看不出这会如何干扰 session ...?
在 Debug模式下,我从 result.ExtraData["accesstoken"] 复制了值,并通过 formscollection(如您在 Facebook.cs 中看到的那样)将其添加到代码中,并且 token 有效。我应该改用 cookie 吗?
AccountController.cs
public ActionResult ExternalLoginCallback(string returnUrl) { AuthenticationResult result = OAuthWebSecurity.VerifyAuthentication( Url.Action("ExternalLoginCallback", new { ReturnUrl = returnUrl })); if (!result.IsSuccessful) { return RedirectToAction("ExternalLoginFailure"); } // Save the accesstoken into session Session["accesstoken"] = result.ExtraData["accesstoken"]; Session["id"] = result.ExtraData["id"]; if (OAuthWebSecurity.Login(result.Provider, result.ProviderUserId, createPersistentCookie: false)) { AddAdditionalPermissions(); return RedirectToLocal(returnUrl); }(...etcetera)
AdditionalPermissions 函数:
private void AddAdditionalPermissions() { string facebook_urlAuthorize_base = "https://graph.facebook.com/oauth/authorize"; string facebook_urlGetToken_base = "https://graph.facebook.com/oauth/access_token"; string facebook_AppID = "1secretappIdhere242341"; string facebook_AppSecret = "1secretcodeheteq4426";
string scope = "publish_stream"; string urlAuthorize = facebook_urlAuthorize_base; urlAuthorize += "?client_id=" + facebook_AppID; urlAuthorize += "&redirect_uri=" + "http://localhost:2730/"; urlAuthorize += "&scope=" + scope; Response.Redirect(urlAuthorize, true); }
Facebook.cs
public void PostToFacebook(FormCollection fm) { var fb = new FacebookClient();
fb = new FacebookClient(HttpContext.Current.Session["accesstoken"].ToString()); var args = new Dictionary<string, object>(); args["message"] = "abc"; fb.Post("/me/feed", args); }
最佳答案
我认为您的 session token cookie 丢失了。尝试不通过替换
来终止当前页面响应Response.Redirect(urlAuthorize, true);
与
Response.Redirect(urlAuthorize, false);
看看有没有帮助。
关于c# - HttpContext.Current.Session ["accesstoken".ToString() 为 null 应该设置值时,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16753717/