问题:

I've seen different methods for posting data to an iframe but I can't find one where I can just send a JSON object. All the methods seem to require me to use form elements to put my data in.

回答1:

Take a look at postMessage and use JSON.stringify for your message and JSON.parse in the event handler.

To actually post to a iframe you have to do

myIframe.contentWindow.postMessage(...)

fiddle

html

<button onclick="_sendMessage ()">Send</button>
<iframe src="" id="myIframe">

javascript

var myIframe = document.getElementById('myIframe');
myIframe.contentWindow.addEventListener('message', function(event) {
    console.log(JSON.parse(event.data));
}, false);


window._sendMessage = function() {
    var json = {payload:'Hello World'};
    myIframe.contentWindow.postMessage(JSON.stringify(json), '*');
}