1 前言
UIBarButtonItem为导航栏按钮，在导航栏的左侧和右侧，他们具有许多种不同的形状和形式。

2 代码讲解
ZYViewController.m

[plain]
 (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    // Do any additional setup after loading the view, typically from a nib. 
    self.view.backgroundColor = [UIColor whiteColor]; 
    self.title = @"First"; 
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Add" style:UIBarButtonItemStylePlain target:self action:@selector(perFormAdd:)];//为导航栏添加右侧按钮 
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(perFormAdd:)];//为导航栏左侧添加系统自定义按钮 
} 
 
-(void)perFormAdd:(id)paramSender{ 
    NSLog(@"Action method got called."); 
} 

- (void)viewDidLoad
{
    [super viewDidLoad];
 // Do any additional setup after loading the view, typically from a nib.
    self.view.backgroundColor = [UIColor whiteColor];
    self.title = @"First";
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Add" style:UIBarButtonItemStylePlain target:self action:@selector(perFormAdd:)];//为导航栏添加右侧按钮
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(perFormAdd:)];//为导航栏左侧添加系统自定义按钮
}

-(void)perFormAdd:(id)paramSender{
    NSLog(@"Action method got called.");
}运行结果：

当点击左边和右边的按钮的时候，控制台显示：

2013-04-23 21:40:58.982 UIBarButtonItemTest[660:c07] Action method got called.

2013-04-23 21:41:02.598 UIBarButtonItemTest[660:c07] Action method got called.

ZYUIBarButtonViewController.m:

[plain]
- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    // Do any additional setup after loading the view. 
    self.view.backgroundColor = [UIColor whiteColor]; 
    self.title = @"Second"; 
    UISwitch *simpleSwitch = [[UISwitch alloc] init];//实例化一个选择开关 
    simpleSwitch.on = YES;//开关设置为开启状态 
    [simpleSwitch addTarget:self action:@selector(switchChanged:) forControlEvents:UIControlEventValueChanged];//添加事件 
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:simpleSwitch];//将开关控件赋给导航栏右按钮 
} 
 
-(void)switchChanged:(UISwitch *)paramSender{ 
    if ([paramSender isOn]) {//如果开关状态为开启 
        NSLog(@"Switch is on."); 
    }else{ 
        NSLog(@"Switch is off."); 
    } 
} 

- (void)viewDidLoad
{
    [super viewDidLoad];
 // Do any additional setup after loading the view.
    self.view.backgroundColor = [UIColor whiteColor];
    self.title = @"Second";
    UISwitch *simpleSwitch = [[UISwitch alloc] init];//实例化一个选择开关
    simpleSwitch.on = YES;//开关设置为开启状态
    [simpleSwitch addTarget:self action:@selector(switchChanged:) forControlEvents:UIControlEventValueChanged];//添加事件
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:simpleSwitch];//将开关控件赋给导航栏右按钮
}

-(void)switchChanged:(UISwitch *)paramSender{
    if ([paramSender isOn]) {//如果开关状态为开启
        NSLog(@"Switch is on.");
    }else{
        NSLog(@"Switch is off.");
    }
}
运行结果：

当拨动开关控制台显示：

2013-04-23 21:46:46.692 UIBarButtonItemTest[727:c07] Switch is off.

2013-04-23 21:46:47.493 UIBarButtonItemTest[727:c07] Switch is on.

UIBarButtonItem导航栏添加按钮