js代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<button onclick="modify()"> modify designMode</button>
<button onclick="register()"> manual register event</button>
<iframe id="nihao">
</iframe>
<script>
var iframe = document.querySelector("#nihao");
//这里注册没有用。因为后面执行了 document.close()
window.addEventListener('cust_event_notify_attr_changed', function (event) {
console.log("=== cust_event_notify_attr_changed from top window ===");
}, false);
iframe.contentWindow.addEventListener('click', function (event) {
console.log("=== onclick iframe click from top window===");
}, false);
iframe.contentWindow.document.open();
iframe.contentWindow.document.write("<!DOCTYPE html> <html><body><h3>nihao</h3></body></html>");
iframe.contentWindow.document.close();
//这里注册才有用。
console.log("== register cust_event_notify_attr_changed ==");
iframe.contentWindow.addEventListener('cust_event_notify_attr_changed', function (event) {
console.log("=== cust_event_notify_attr_changed from iframe===");
}, false);
iframe.contentWindow.addEventListener('click', function (event) {
console.log("=== onclick iframe click from iframe===");
}, false);
iframe.contentWindow.document.designMode = "on";
function modify() {
document.querySelector("#nihao").contentWindow.document.designMode = "off";
}
function register() {
var iframe = document.querySelector("#nihao");
iframe.contentWindow.addEventListener('cust_event_notify_attr_changed', function (event) {
console.log("=== cust_event_notify_attr_changed from iframe again===");
}, false);
iframe.contentWindow.addEventListener('click', function (event) {
console.log("=== onclick iframe click===");
}, false);
}
</script>
</body>
</html>