I contentWindow to get the elements of the page in iframe.
this error will be reported if there is no cross-domain in the chrome browser:
ERROR DOMException: Blocked a frame with origin "http://localhost:8100" from accessing a cross-origin frame.
, and the error will not be reported on the Android tablet.
but in the iOS tablet and safari will report errors Uncaught SecurityError, found a lot, still do not know how to solve, ask for God"s help!