FBSession 必须指定解析

Question

我正在尝试按照使用 Facebook 登录的 Parse 教程进行操作。但是，示例代码与指南不符，所以那里的代码没有用。我已完全按照指南操作，但在我登录后，它会将我定向到 Facebook 应用程序，我授予权限，它会返回到我正在构建的应用程序，但我收到以下错误

FBSDKLog: Error for request to endpoint 'me': An open FBSession must be specified for calls to this endpoint.

这是怎么回事？在登录控制器中：

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];


    FBRequest *request = [FBRequest requestForMe];
    [request startWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
        if (!error) {
            // handle successful response
        } else if ([[[[error userInfo] objectForKey:@"error"] objectForKey:@"type"]
                    isEqualToString: @"OAuthException"]) { // Since the request failed, we can check if it was due to an invalid session
            NSLog(@"The facebook session was invalidated");
            [self logoutButtonAction:nil];
        } else {
            NSLog(@"Some other error: %@", error);
        }
    }];
    if ([PFUser currentUser] && // Check if user is cached
        [PFFacebookUtils isLinkedWithUser:[PFUser currentUser]]) { // Check if user is linked to Facebook
        // Present the next view controller without animation
        [self _presentUserDetailsViewControllerAnimated:NO];
    }
}
- (IBAction)loginButtonTouchHandler:(id)sender  {
    // Set permissions required from the facebook user account
    NSArray *permissionsArray = @[ @"user_about_me", @"user_relationships", @"user_birthday", @"user_location"];
    [PFFacebookUtils initializeFacebook];
    // Login PFUser using Facebook
    [PFFacebookUtils logInWithPermissions:permissionsArray block:^(PFUser *user, NSError *error) {
        [_activityIndicator stopAnimating]; // Hide loading indicator

        if (!user) {
            NSString *errorMessage = nil;
            if (!error) {
                NSLog(@"Uh oh. The user cancelled the Facebook login.");
                errorMessage = @"Uh oh. The user cancelled the Facebook login.";
            } else {
                NSLog(@"Uh oh. An error occurred: %@", error);
                errorMessage = [error localizedDescription];
            }
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Log In Error"
                                                            message:errorMessage
                                                           delegate:nil
                                                  cancelButtonTitle:nil
                                                  otherButtonTitles:@"Dismiss", nil];
            [alert show];
        } else {
            if (user.isNew) {
                NSLog(@"User with facebook signed up and logged in!");
            } else {
                NSLog(@"User with facebook logged in!");
            }
            [self _presentUserDetailsViewControllerAnimated:YES];
        }
    }];

    [_activityIndicator startAnimating]; // Show loading indicator until login is finished
}

- (void)_presentUserDetailsViewControllerAnimated:(BOOL)animated {
    UserDetailsViewController *detailsViewController = [[UserDetailsViewController alloc] init];
    [self.navigationController pushViewController:detailsViewController animated:YES];
}

在我的 UserDetailsViewController 中：

- (void)viewDidLoad {
    // ...
    [self _loadData];
}

- (void)_loadData {
    // ...
    FBRequest *request = [FBRequest requestForMe];
    [request startWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
        if (!error) {
            // result is a dictionary with the user's Facebook data
            NSDictionary *userData = (NSDictionary *)result;

            NSString *facebookID = userData[@"id"];
            NSString *name = userData[@"name"];
            NSString *location = userData[@"location"][@"name"];
            NSString *gender = userData[@"gender"];
            NSString *birthday = userData[@"birthday"];
            NSString *relationship = userData[@"relationship_status"];

            NSURL *pictureURL = [NSURL URLWithString:[NSString stringWithFormat:@"https://graph.facebook.com/%@/picture?type=large&return_ssl_resources=1", facebookID]];
            // URL should point to https://graph.facebook.com/{facebookId}/picture?type=large&return_ssl_resources=1
                       NSURLRequest *urlRequest = [NSURLRequest requestWithURL:pictureURL];

            // Run network request asynchronously
            [NSURLConnection sendAsynchronousRequest:urlRequest
                                               queue:[NSOperationQueue mainQueue]
                                   completionHandler:
             ^(NSURLResponse *response, NSData *data, NSError *connectionError) {
                 if (connectionError == nil && data != nil) {
                     // Set the image in the header imageView
                     self.headerImageView.image = [UIImage imageWithData:data];
                 }
             }];

            // Now add the data to the UI elements
            // ...
        }
    }];

}

Answer 1

我们在尝试使用此功能创建自动登录功能时想通了：

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    FBRequest *request = [FBRequest requestForMe];
    [request startWithCompletionHandler:^(FBRequestConnection *connection, id result, NSError *error) {
        if (!error) {
            // handle successful response
        } else if ([[[[error userInfo] objectForKey:@"error"] objectForKey:@"type"]
                isEqualToString: @"OAuthException"]) { // Since the request failed, we can check if it was due to an invalid session
            NSLog(@"The facebook session was invalidated");
            [self logoutButtonAction:nil];
        } else {
            NSLog(@"Some other error: %@", error);
        }
    }];
    if ([PFUser currentUser] && // Check if user is cached
        [PFFacebookUtils isLinkedWithUser:[PFUser currentUser]]) { // Check if user is linked to Facebook
        // Present the next view controller without animation
        [self _presentUserDetailsViewControllerAnimated:NO];
    }
}

我们实际上跳过了 [PFFacebookUtils initializeFacebook] 调用，因为它只在您按下登录按钮时发生。解决方案是将此调用放在方法 application:didFinishLaunchingWithOptions:

中的 appDelegate 中

FBSession 必须指定解析

FBSession Must Be Specified Parse

facebook

facebook-graph-api

ios

parse-platform