ios - Facebook 登录 您已经授权 APP_NAME

Question

我在使用 facebook 登录时遇到问题。我将 Facebook 集成到我的应用程序中。用户第一次登录时，它显示登录页面，但从下一次开始，它会转到“您已经授权 APP_NAME”页面。

我检查了 Scrumptious 教程，这是我从 Facebook SDK 获得的示例。它的工作方式也一样。

我想从不同的用户登录，我不希望每次都出现“您已经授权 APP_NAME”的页面。

如何解决这个问题。

Answer 1

在您的应用委托(delegate)类中尝试此代码。

它会检查 session 是否打开，并在您关闭连接时从设备缓存中清除您的登录凭据。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    LoginVC *loginScreen=[[LoginVC alloc]initWithNibName:@"LoginVC" bundle:nil];

    navigationController=[[UINavigationController alloc]initWithRootViewController:loginScreen];

    self.navigationController.navigationBar.tintColor = [UIColor blackColor];
    self.window.rootViewController=self.navigationController;
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];

    // See if we have a valid token for the current state.
    if (FBSession.activeSession.state == FBSessionStateCreatedTokenLoaded) {
        [self openSession];
        // To-do, show logged in view
    } else {
        // No, display the login page.
        [self showLoginView];
    }
    return YES;


}
- (void)sessionStateChanged:(FBSession *)session
                      state:(FBSessionState) state
                      error:(NSError *)error
{
    switch (state) {
        case FBSessionStateOpen: {
            UIViewController *topViewController =
            [self.navigationController topViewController];
            if ([[topViewController presentedViewController]
                 isKindOfClass:[LoginVC class]]) {
                [topViewController dismissViewControllerAnimated:YES completion:nil];
            }
        }
            break;
        case FBSessionStateClosed:
        case FBSessionStateClosedLoginFailed:
            // Once the user has logged in, we want them to
            // be looking at the root view.
            [self.navigationController popToRootViewControllerAnimated:NO];

            [FBSession.activeSession closeAndClearTokenInformation];

            [self showLoginView];
            break;
        default:
            break;
    }

    if (error) {
        UIAlertView *alertView = [[UIAlertView alloc]
                                  initWithTitle:@"Error"
                                  message:error.localizedDescription
                                  delegate:nil
                                  cancelButtonTitle:@"OK"
                                  otherButtonTitles:nil];
        [alertView show];
    }
}

- (void)openSession
{
    [FBSession openActiveSessionWithReadPermissions:nil
                                       allowLoginUI:YES
                                  completionHandler:
     ^(FBSession *session,
       FBSessionState state, NSError *error) {
         [self sessionStateChanged:session state:state error:error];
     }];
}

- (BOOL)application:(UIApplication *)application
            openURL:(NSURL *)url
  sourceApplication:(NSString *)sourceApplication
         annotation:(id)annotation
{
    return [FBSession.activeSession handleOpenURL:url];
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    // We need to properly handle activation of the application with regards to Facebook Login
    // (e.g., returning from iOS 6.0 Login Dialog or from fast app switching).
    [FBSession.activeSession handleDidBecomeActive];
}

我希望这段代码会有所帮助。