UiViewController需要很长时间才能显示

Question

然后我有一个被实例化并通过方法显示的UIViewController类，问题在于self.present视图的结束没有完全显示，但只有一部分显示，大约5-6秒后，视图的其余部分也会显示！如何让视图完全出现在self.present的末尾？

SWIFT代码：

    ///First Method (It's call nextviewcontroller
    var ret: Bool = false
            let c = c(c: self.c!)

            c.crea(n: self.txtn.text!, completion: { result in
                ret = result
            })


            if(ret == true)
            {
                let viewnext = NextViewController(c: c)
                self.present(viewnext, animated: true, completion: { () in print("Done") })

            }

  //NextViewController.swift
class NextViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

    //Oggetti Privati
    private var TextViewDesc: UITextView = UITextView()
    private var pickerviewStato: UIPickerView = UIPickerView()
    private var labelnameINFO: UILabel = UILabel()
    private var labelClientINFO: UILabel = UILabel()
    private var labelfilINFO: UILabel = UILabel()
    private var labelClient: UILabel = UILabel()
    private var labelfil: UILabel = UILabel()
    private var buttonris: UIButton = UIButton(type: .custom)
    private var buttonKilometri = UIButton(type: .custom)
    private var buttonfield = UIButton(type: .custom)
    private var buttonprint = UIButton(type: .custom)
    private var buttonReturn = UIButton()
    private let statoCantiere = ["InCorso", "Chiuso", "Lavoro terminato inserire bolle"]
    private var immagineStatoCantiere: UIImageView = UIImageView()
    private let DistLtoR: CGFloat = 130
    private let DistRtoL: CGFloat = 50
    //Oggetti Pubblici
    var c: c

    init(c: c) {
        c = c
        super.init(nibName: nil, bundle: nil)
    }
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        hideKeyboardWhenTappedAround()
        self.view.backgroundColor = UIColor.white
        initView()
    }

    func initView() {

        labelnameINFO = UILabel(frame: CGRect(x: 20, y: 60, width: 120, height: 21))
        labelnameINFO.text = "Cantiere:"
        labelnameINFO.font = UIFont(name: "HelveticaNeue-Bold", size: 16.0)
        self.view.addSubview(labelnameINFO)
        let labelname = UILabel(frame: CGRect(x: 100, y: 60, width: 200, height: 21))
        labelname.text = CantiereInterno.Getname()
        self.view.addSubview(labelname)
        labelClientINFO = UILabel(frame: CGRect(x: 20, y: 100, width: 130, height: 21))
        labelClientINFO.text = "Ragione Sociale:"
        labelClientINFO.font = UIFont(name: "HelveticaNeue-Bold", size: 16.0)
        self.view.addSubview(labelClientINFO)
        labelClient = UILabel(frame: CGRect(x: 180, y: 100, width: 180, height: 21))
        labelClient.text = c.GetRagioneSociale()
        self.view.addSubview(labelClient)
        //Configurazioe label fil
        labelfilINFO = UILabel(frame: CGRect(x: 20, y: 140, width: 130, height: 21))
        labelfilINFO.text = "fil:"
        labelfilINFO.font = UIFont(name: "HelveticaNeue-Bold", size: 16.0)
        self.view.addSubview(labelfilINFO)
        labelfil = UILabel(frame: CGRect(x: 100, y: 140, width: 180, height: 21))
        labelfil.text = c.Getfil()
        self.view.addSubview(labelfil)
        let labelStato = UILabel(frame: CGRect(x: 20, y: 190, width: 130, height: 21))
        labelStato.text = "Stato:"
        labelStato.font = UIFont(name: "HelveticaNeue-Bold", size: 16.0)
        self.view.addSubview(labelStato)
        self.pickerviewStato = UIPickerView(frame: CGRect(x: 90, y: 180, width: 160, height: 50))
        self.pickerviewStato.delegate = self as UIPickerViewDelegate
        self.pickerviewStato.dataSource = self as UIPickerViewDataSource
        self.pickerviewStato.backgroundColor = UIColor.gray
        self.view.addSubview(pickerviewStato)
        immagineStatoCantiere = UIImageView(frame: CGRect(x: (self.view.frame.width / 2) + 50, y: 180, width: 50, height: 50));
        immagineStatoCantiere.image = UIImage(named: "InCorso.png")
        immagineStatoCantiere.backgroundColor = UIColor.gray
        self.view.addSubview(immagineStatoCantiere)
        self.TextViewDesc = UITextView(frame: CGRect(x: 0, y: 250, width: self.view.frame.width, height: 80))
        self.automaticallyAdjustsScrollViewInsets = false
        TextViewDesc.font = UIFont(name: "HelveticaNeue-Bold", size: 18.0)
        TextViewDesc.textAlignment = NSTextAlignment.justified
        TextViewDesc.textColor = UIColor.blue
        TextViewDesc.isEditable = true
        TextViewDesc.backgroundColor = UIColor.lightGray
        TextViewDesc.text = c.GetDescrizioneEstesa()
        self.view.addSubview(TextViewDesc)
        buttonris.frame = CGRect(x: (self.view.frame.width / 2) - DistLtoR, y: 380, width: 100, height: 100)
        buttonris.layer.cornerRadius = 0.5 * buttonris.bounds.size.width
        buttonris.clipsToBounds = true
        buttonris.setImage(UIImage(named: "risorse_umane.png"), for: .normal)
        buttonris.backgroundColor = UIColor.lightGray
        buttonris.addTarget(self, action: #selector(risbuttonAction), for: .touchUpInside)
        self.view.addSubview(buttonris)
        buttonKilometri.frame = CGRect(x: (self.view.frame.width / 2) + DistRtoL, y: 380, width: 100, height: 100)
        buttonKilometri.layer.cornerRadius = 0.5 * buttonKilometri.bounds.size.width
        buttonKilometri.clipsToBounds = true
        buttonKilometri.setImage(UIImage(named: "kilometri.png"), for: .normal)
        buttonKilometri.backgroundColor = UIColor.lightGray
        buttonKilometri.addTarget(self, action: #selector(KilometributtonAction), for: .touchUpInside)
        self.view.addSubview(buttonKilometri)
        buttonfield.frame = CGRect(x: (self.view.frame.width / 2) - DistLtoR, y: 500, width: 100, height: 100)
        buttonfield.layer.cornerRadius = 0.5 * buttonfield.bounds.size.width
        buttonfield.clipsToBounds = true
        buttonfield.setImage(UIImage(named: "field.png"), for: .normal)
        buttonfield.backgroundColor = UIColor.lightGray
        buttonfield.addTarget(self, action: #selector(fieldbuttonAction), for: .touchUpInside)
        self.view.addSubview(buttonfield)
        buttonprint.frame = CGRect(x: (self.view.frame.width / 2) + DistRtoL, y: 500, width: 100, height: 100)
        buttonprint.layer.cornerRadius = 0.5 * buttonfield.bounds.size.width
        buttonprint.clipsToBounds = true
        buttonprint.setImage(UIImage(named: "print.png"), for: .normal)
        buttonprint.backgroundColor = UIColor.lightGray
        buttonprint.addTarget(self, action: #selector(RapportinobuttonAction), for: .touchUpInside)
        self.view.addSubview(buttonprint)
        buttonprint.isHidden = false
        buttonReturn.frame = CGRect(x: (self.view.frame.width / 2), y: 600, width: 80, height: 80)
        buttonReturn.backgroundColor = UIColor.white
        buttonReturn.setImage(UIImage(named: "return.png"), for: .normal)
        buttonReturn.setTitle("Go Home", for: .normal)
        buttonReturn.addTarget(self, action: #selector(ReturnToHomebuttonAction), for: .touchUpInside)
        self.view.addSubview(buttonReturn)
    }

Answer 1

在viewwillappear中调用initView：

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    if labelnameINFO == nil{
        self.initView()
    }
}