iOS中隐藏UINavigationBar的方法

如果想在root view controller中把UINavigationBar隐藏，如何做呢？其实我们只需要实现UINavigationController的一个delegate方法就行了。代码如下：

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
	if ( viewController ==  rootViewController) {
		[navigationController setNavigationBarHidden:YES animated:animated];
	} else if ( [navigationController isNavigationBarHidden] ) {
		[navigationController setNavigationBarHidden:NO animated:animated];
	}
}