Swift WebView内容宽度超出时不居中

不居中代码

  let javascript = "var meta = document.createElement('meta');meta.setAttribute('name', 'viewport');meta.setAttribute('content', 'width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no');document.getElementsByTagName('head')[0].appendChild(meta);"

去掉 initial-scale=1.0 内容显示正常

let javascript = "var meta = document.createElement('meta');meta.setAttribute('name', 'viewport');meta.setAttribute('content', 'width=device-width,maximum-scale=1.0, user-scalable=no');document.getElementsByTagName('head')[0].appendChild(meta);"