Facebook登录您已授权APP_NAME

Question

I have problem with facebook Login..I integrated Facebook into my app.First time when user wants to login it is showing login page,but from next time it is going to page "You have already authorised APP_NAME".

I checked for Scrumptious tutorial which is the sample which I got from Facebook SDK.and it is also working like same.

I want to login from different user,I dont want that page "You have already authorised APP_NAME" every time.

How to solve this.

Answer 1

Try this code in your app delegate class.

It checks whether the session is open or not and clears your login credentials from the device cache when you close the connection.

- (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];
}

I hope this code will be helpful.