postMessage没接收到值只接收到webpackOk

原因

当时的iframe是动态生成的，未加载好就发送postMessage，webpack帮助了发送，所以出现webpackOk

解决方案

const targetIframe = document.getElementById('targetIframe')
const info = { sign: '标识' }
targetIframe.onload = () => {
    targetIframe.contentWindow.postMessage(info,'*')
}