setViewControllers([subjective], direction: .Forward, animated: true, completion: nil)

setViewControllers([firstVC], direction: .Forward, animated: true, completion: nil)

import UIKit

class PageVC : UIPageViewController, UIPageViewControllerDelegate, UIPageViewControllerDataSource {

var lblhoten = String()
var lblngaysinh = String()
var lblsodt = String()

lazy var VCArr: [UIViewController] = {
    return [self.VCInstance("ThongTinBNPage2"),
            self.VCInstance("ThongTinBNPage3")]
}()

private func VCInstance(name: String) -> UIViewController {
    return UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier(name)
}

override func viewDidLoad() {
    super.viewDidLoad()
    self.dataSource = self
    self.delegate = self
    if let firstVC = VCArr.first {
        let subjective = self.storyboard?.instantiateViewControllerWithIdentifier("ThongTinBNPage2") as! VCSubjective
        subjective.lblhoten = lblhoten
        subjective.lblngaysinh = lblngaysinh
        subjective.lblsodt = lblsodt
        setViewControllers([subjective], direction: .Forward, animated: true, completion: nil)
    }
}

public func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
    guard let viewcontrollerindex = VCArr.indexOf(viewController) else {
        return nil
    }

    let previousindex = viewcontrollerindex - 1


    guard previousindex >= 0 else {
        return VCArr.last
    }

    guard VCArr.count > previousindex else {
        return nil
    }

    return VCArr[previousindex]
}

public func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
    guard let viewcontrollerindex = VCArr.indexOf(viewController) else {
        return nil
    }

    let nextindex = viewcontrollerindex + 1


    guard nextindex < VCArr.count else {
        return VCArr.first
    }

    guard VCArr.count > nextindex else {
        return nil
    }

    return VCArr[nextindex]
}

public func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
    return VCArr.count
}

// The selected item reflected in the page indicator.
public func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
    guard let firstviewcontroller = viewControllers?.first,
        let firstviewcontrollerindex = VCArr.indexOf(firstviewcontroller) else {
            return 0
    }

    return firstviewcontrollerindex
}