当页面显示时一直奔溃，错误提示-[UICachedDeviceWhiteColor pointSize]: unrecognized selector sent to instance
原因是设置导航字体颜色时[self.navigationController.navigationBar setTitleTextAttributes:@{NSFontAttributeName:[UIColor whiteColor]}];搞错了写成了设置字号了，正确应该是[self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor whiteColor]}];还是在stackoverflow上面找到了解释。
原文：http://www.cnblogs.com/chenhongios/p/6006251.html