ViewController.swift
//    WKWebView
    lazy var wkwebView: WKWebView = {
        var webView = WKWebView(frame: self.view.bounds)
        webView.uiDelegate = self
        webView.navigationDelegate = self
        webView.isUserInteractionEnabled = true
        //ここ
        webView.scrollView.bounces = false
        return webView
    }()