Front-end cross-domain method window. Postmessage__javascript

One, window. PostMessage is suitable for cross domain communication within different windows of the same page. This method allows you to communicate across windows, regardless of whether the two windows are homologous. Second, for example, the parent window http://127.0.0.1:3000/index.html to the child window http://127.0.0.1:3001/index.html send a message, call the PostMessage method on the line. (who sends the message, first gets its window object, such as the parent window sends a message to the child window, first gets the child window object, and then calls the PostMessage method) as follows:
Window.postmessage (Messages, origin) message: Specific Information content origin: the source of receiving messages four, Window.addeventlistener (' message ', callback, False) listens to messages sent by the other side by listening for message events. Callback:function (event) {}//event three properties are {Source: The window that sends the message origin: the domain name of the message sent: message sent}