ViewController.m

@interface ViewController ()
{
    NSString *name;
    NSString *email ;
    NSString *acessToken;
}
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:YES];
    
    UILabel *nameLabel = [[UILabel alloc]initWithFrame:CGRectMake(100, 100, 200, 50)];
    nameLabel.text = name;
    nameLabel.textColor = [UIColor blackColor];
    [self.view addSubview:nameLabel];
    
    UILabel *emailLabel = [[UILabel alloc]initWithFrame:CGRectMake(100, 150, 200, 50)];
    emailLabel.text = email;
    [self.view addSubview:emailLabel];
    
    UILabel *accessTokenLabel = [[UILabel alloc]initWithFrame:CGRectMake(100, 200, 200, 50)];
    accessTokenLabel.text = acessToken;
    [self.view addSubview:accessTokenLabel];
    
    
    UIButton *myLoginButton=[UIButton buttonWithType:UIButtonTypeCustom];
    myLoginButton.backgroundColor=[UIColor darkGrayColor];
    myLoginButton.frame=CGRectMake(0,0,300,40);
    myLoginButton.center = self.view.center;
    [myLoginButton setTitle: @"My Login Button" forState: UIControlStateNormal];
    [myLoginButton addTarget:self
                      action:@selector(loginButtonClicked) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:myLoginButton];
    
}


-(void)loginButtonClicked
{
    FBSDKLoginManager *login = [[FBSDKLoginManager alloc] init];
    [login
     logInWithReadPermissions: @[@"public_profile",@"user_friends",@"email"]
     fromViewController:self
     handler:^(FBSDKLoginManagerLoginResult *result, NSError *error) {
         if (error) {
             NSLog(@"Process error");
         } else if (result.isCancelled) {
             NSLog(@"Cancelled");
         } else {
             NSLog(@"Logged in");
             
             NSLog(@"Result %@",result);
    
         }
     }];
    
    FBSDKGraphRequest *request = [[FBSDKGraphRequest alloc]
                                  initWithGraphPath:@"/me"
                                  parameters:@{ @"fields": @"id,name,email"}
                                  HTTPMethod:@"GET"];
    [request startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) {
    
        NSLog(@"resds %@",result);
        name = [result valueForKey:@"name"];
        email = [result valueForKey:@"email"];
        acessToken = [result valueForKey:@"id"];
    
    }];
   
}