//去除导航栏下方的横线
[self.navigationController.navigationBar setBackgroundImage:[UIImage createImageWithColor:RGBCOLOR(36, 150, 218, 1)]
forBarPosition:UIBarPositionAny
barMetrics:UIBarMetricsDefault];
[self.navigationController.navigationBar setShadowImage:[UIImage new]];
原文:http://www.cnblogs.com/wq-gril/p/5144048.html