NavigationController

Navigation Controller以一个栈的形式维护VC，通过pushViewController入栈，popViewController出栈。

页面分几部分：Navigation bar, Custom Content和Navigation toolbar

1.Navigation bar

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1.简单实用

UIBarButtonItem *leftButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(selectLeftAction:)];

self.navigationItem.leftBarButtonItem = leftButton;

UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd  target:self action:@selector(selectRightAction:)];

self.navigationItem.rightBarButtonItem = rightButton;

2.还有一些系统提供的自定义风格的button形式，详细内容

3.titleView

titleView可以替换成button，或者SegmentedControl，具体方法参见

2.Navigation toolbar

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toolbar使用

hidesBottomBarWhenPushed

http://blog.csdn.net/holydancer/article/details/8097585