从Facebook App登录返回iOS的零令牌响应

Question

I set Login Behaviour FBSDKLoginBehaviorSystemAccount and try to login, then my app fetch details from Settings of Facebook then its give me successfully response in this class FBSDKLoginManagerLoginResult object which include token string and user id . But if there is no account added in setting of Facebook then this move user to Facebook App and after authentication when move back to app but this return nil token and no other details. I don't know why this is happening I added some code in following. I hope every one understand my problem those who performed login from Facebook in iOS Development and someone still no then kindly tell me will add more details.

if (![self isCurrentAccessTokenValid] ) {
        self.FBLoginManager.loginBehavior = FBSDKLoginBehaviorSystemAccount;
        [self.FBLoginManager logInWithReadPermissions:@[ @"email",@"public_profile",@"user_friends"] handler:
         ^(FBSDKLoginManagerLoginResult *result, NSError *error) {
             block(result, error);
             NSLog(@"%@",result.token.tokenString);
             NSLog(@"%@",result.token.userID);
             //NSLog(@"%hhd",result.isCancelled);

             [FBSDKAccessToken setCurrentAccessToken:result.token];

        }];
    } else {
        [self fetchUserProfile:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) {
            block(result, error);
        }];
    }

Looking for helpful response. Thanks.

Answer 1

Try this

FBSDKLoginManager *login = [[FBSDKLoginManager alloc] init];
    [login
     logInWithReadPermissions: @[@"public_profile", @"email", @"user_friends"]
     handler:^(FBSDKLoginManagerLoginResult *result, NSError *error) {
         if (error) {
             NSLog(@"Process error");
         } else if (result.isCancelled) {
             NSLog(@"Cancelled");
         } else {
             NSLog(@"Logged in");             
         }
     }];