打破iframe安全限制的3种方案

http://www.ayqy.net/blog/%E6%89%93%E7%A0%B4iframe%E5%AE%89%E5%85%A8%E9%99%90%E5%88%B6%E7%9A%843%E7%A7%8D%E6%96%B9%E6%A1%88/