         pdfView.autoScales = true
         pdfView.displaysPageBreaks = false
         pdfView.displayBox = .cropBox
+        pdfView.displayMode = .singlePageContinuous
         
         
         let center = NotificationCenter.default

    
    let userDeaults = UserDefaults.standard
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        

    }
    
    func moveToLastReadingProsess() {
        var pageIndex = 0
        if self.userDeaults.object(forKey: (self.pdfView.document?.documentURL?.path)!) != nil {
            // key exists
            pageIndex = self.userDeaults.integer(forKey: (self.pdfView.document?.documentURL?.path)!)
        } else if verticalWriting {
            // 初めて読む　且つ　縦書き
            pageIndex = (self.pdfView.document?.pageCount)! - 1
        }
        
        // TODO: if pageIndex == pageCount - 1, then go to last CGRect
        self.pdfView.go(to: (self.pdfView.document?.page(at: pageIndex)!)!)
    }
    
