index.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>跨域POST消息发送</title>
    <script type="text/JavaScript">
        // const HOST = 'http://192.168.0.156:5500/';
        // const page = `${HOST}/bi-service/api/file/index.html`;
        // sendPost 通过postMessage实现跨域通信将表单信息发送到 moweide.gitcafe.io上,
        // 并取得返回的数据
        function sendPost() {
            // 获取id为otherPage的iframe窗口对象
            var iframeWin = document.getElementById("otherPage").contentWindow;
            // 向该窗口发送消息
            iframeWin.postMessage({
                    "type": "change_color",
                    "payload": {
                        "id": "004",
                        "color": "0xFF00FF"
                    }
                },
                'http://127.0.0.1:9000');// 这里是 child页面的域名
        }
        // 监听跨域请求的返回
        window.addEventListener("message", function(event) {
            console.log(event, event.data);
        }, false);
    </script>
</head>
<body>
<textarea id="message"></textarea>
<input type="button" value="发送" onclick="sendPost()">
<iframe
        src="http://127.0.0.1:9000" id="otherPage" style="height: 900px;width: 900px"></iframe>
</body>

</html>