如何在WKWebview中设置比例？

// 创建WKWebView的配置对象
let configuration = WKWebViewConfiguration()

// 创建WKUserContentController对象
let userContentController = WKUserContentController()

// 创建一个WKUserScript对象，用于设置视口的比例
let scriptSource = "var meta = document.createElement('meta'); meta.setAttribute('name', 'viewport'); meta.setAttribute('content', 'width=device-width, initial-scale=0.5'); document.getElementsByTagName('head')[0].appendChild(meta);"
let userScript = WKUserScript(source: scriptSource, injectionTime: .atDocumentEnd, forMainFrameOnly: true)

// 将WKUserScript对象添加到WKUserContentController对象中
userContentController.addUserScript(userScript)

// 将WKUserContentController对象赋值给配置对象的userContentController属性
configuration.userContentController = userContentController

// 创建WKWebView并传入配置对象
let webView = WKWebView(frame: .zero, configuration: configuration)