I have a project whose `rootViewController` is a `UINavigationController`, and in my project only the view controller loading a full screen `UIWebView`. I need to change its orientation.

I have finished fixing the issue, but there's some trouble: When a user is in the view controller with the web view in the *landscape orientation* then clicks the back button, the previous view controller is also in landscape orientation. I want it to be in portrait, however. Any ideas on how to do this?

If you can read Chinese, I found [this page](http://www.cocoachina.com/ask/questions/show/121091/%E5%AF%BC%E8%88%AA%E6%8E%A7%E5%88%B6%E5%99%A8%E4%B8%BA%E6%A0%B9%E6%8E%A7%E5%88%B6%E5%99%A8%E7%9A%84%E9%A1%B9%E7%9B%AE%E4%B8%AD%E6%A8%AA%E5%B1%8F%E8%BF%94%E5%9B%9E%E5%90%8E%E5%BC%BA%E5%88%B6%E7%AB%96%E5%B1%8F%E6%80%8E%E4%B9%88%E5%81%9A), thanks.