iframe内嵌页面——跨域通讯

<template>
  <div class="act-form">
    <iframe
      :src="src"
      ref="iframe"
      frameborder="no"
      align="middle"
      width="100%"
      height="600px"
      scrolling="auto" />
    <el-button @click="sendMessage">向iframe发送信息</el-button>
  </div>
</template>
<script>
export default {
  data () {
    return {
      src: '',
      iframeWin: null,
      isLoaded: false
    }
  },
  created () {
        this.src = 'https://odp.oa.com'

　　//获取iframe
　　var oIframe=document.getElementsByTagName('iframe')[0];

　　//获取iframe中的元素
　　var oText=oIframe.contentWindow.document.getElementById('navContent');

　　//改变iframe中元素的属性
　　oIframe.contentWindow.document.getElementById('navContent').style.color='red';

  },
  mounted () {
    // 在外部vue的window上添加postMessage的监听，并且绑定处理函数handleMessage
    window.addEventListener('message', this.handleMessage)
    this.iframeWin = this.$refs.iframe.contentWindow
  },
  methods: {
    sendMessage () {
      console.log(this.iframeWin, 1111111)
      this.iframeWin.postMessage({
        cmd: 'getFormJson',
        params: {}
      }, '*')
    },
    async handleMessage (event) {
      // console.log(event, 222222)
      const data = event.data
      // console.log(data, 333333)
      switch (data.cmd) {
      case 'returnFormJson':
        break
      case 'returnHeight':
        break
      }
    },
    async enroll (data) {
      console.log('4444444')
    }
  }
}
</script>
<template>
  <div class="act-for