相关疑难解决方法(0)

我的facebook访问令牌为空,尽管按钮显示我已登录.任何人都知道为什么会这样？

来自RootViewController.m

- (void)viewDidLoad {
    [super viewDidLoad];

    self->login_button = [[FBSDKLoginButton alloc] init];
    self->login_button.center = self.view.center;
    [self.view addSubview:self->login_button];

    FBSDKAccessToken* access_token =[FBSDKAccessToken currentAccessToken];
    NSLog(@"Access Token, %@",access_token);
}

来自ApplicationDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    [self.window setRootViewController:[[RootViewController alloc] init]];

    [self.window makeKeyAndVisible];

    [self.window setBackgroundColor:[UIColor purpleColor]];
    [FBSDKLoginButton class];
    return [[FBSDKApplicationDelegate sharedInstance] application:application didFinishLaunchingWithOptions:launchOptions];
}

我的-ObjC链接器标志也已设置