http://blog.csdn.net/zww1984774346/article/details/50608338
http://blog.csdn.net/zww1984774346/article/details/50506502
http://jingyan.baidu.com/article/c14654139fa3a20bfcfc4cb2.html
在xcode8里面使用storyboard ，发现IB有问题找不到类的报错。通过导入model解决这个问题
http://*.com/questions/1725881/unknown-class-myclass-in-interface-builder-file-error-at-runtime#