invalid_token尝试通过ACAccount和SLRequest访问Facebook时

Question

我正在尝试从用户的Facebook收件箱中读取邮件，但是我遇到了一个拒绝我访问的错误。这是我的代码：

ACAccountStore *accountStore = [[ACAccountStore alloc] init];
    ACAccountType *fbAccountType = [accountStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierFacebook];
    NSDictionary *options = @{
                              ACFacebookAppIdKey : FacebookAppKey,
                              ACFacebookPermissionsKey : FacebookPermissionsArray
                              };
    [accountStore requestAccessToAccountsWithType:fbAccountType options:options completion:^(BOOL granted, NSError *error)
     {
         if (error || !granted) {
             return;
         }
         NSArray *accounts = [accountStore accountsWithAccountType:fbAccountType];
         if (accounts.count == 0) {
             return;
         }
         ACAccount *facebookAccount = [accounts lastObject];
         NSURL *inboxURL = [NSURL URLWithString:@"https://graph.facebook.com/me/inbox"];
         NSMutableDictionary *parameters = [[NSMutableDictionary alloc] init];
         SLRequest *facebookInfoRequest = [SLRequest requestForServiceType:SLServiceTypeFacebook
                                                             requestMethod:SLRequestMethodGET
                                                                       URL:inboxURL
                                                                parameters:parameters];
         [facebookInfoRequest setAccount:facebookAccount];
         [facebookInfoRequest performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
             NSLog(@"response data: %i, url response: %@, error: %@", responseData.length, urlResponse, error);
         }];
     }];

对此的 URL 回应如下：

<NSHTTPURLResponse: 0xcb5fa10> { URL: https://graph.facebook.com/me/inbox?access_token=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX } { status code: 400, headers {
    "Access-Control-Allow-Origin" = "*";
    "Cache-Control" = "no-store";
    Connection = "keep-alive";
    "Content-Length" = 194;
    "Content-Type" = "application/json; charset=UTF-8";
    Date = "Tue, 18 Feb 2014 15:29:36 GMT";
    Expires = "Sat, 01 Jan 2000 00:00:00 GMT";
    Pragma = "no-cache";
    "Www-Authenticate" = "OAuth "Facebook Platform" "invalid_token" "Error validating access token: Session has expired on Feb 13, 2014 6:17am. The current time is Feb 18, 2014 7:29am."";
    "X-FB-Debug" = "XXXXXXXXXXXXXXXX/Y+K0w=";
    "X-FB-Rev" = XXXXXXXX;
} }

我不确定为什么会出现这个问题。我在这里可能做错了什么？

Answer 1

设备上的Facebook帐户与服务器和SDK的缓存不同步。要强制更新，只需调用ACAccountStore's方法renewCredentialsForAccount。

- (void)refreshFacebookTokenStatus
{
    ACAccountStore *accountStore;
    ACAccountType *accountTypeFB;
    if ((accountStore = [[ACAccountStore alloc] init]) &&
        (accountTypeFB = [accountStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierFacebook]))
    {
        NSArray *fbAccounts = [accountStore accountsWithAccountType:accountTypeFB];
        id account;
        if (fbAccounts && [fbAccounts count] > 0 && (account = [fbAccounts objectAtIndex:0]))
        {
            [accountStore renewCredentialsForAccount:account 
                                          completion:^(ACAccountCredentialRenewResult renewResult, NSError *error)
            {
                if (error)
                {
                    NSLog(@"%@", error.localizedDescription);
                }
            }];
        }
    }
}

最简单的方法是在每次应用启动时调用它，但这可能效率不高。因此，最好在会话状态更改发生时调用它。

此外，请确保您的 Facebook 应用设置没有开启Sandbox选项，如果您尝试使用非应用开发者 Facebook 用户登录。