navigation controller

- (void)viewDidLoad {
    [super viewDidLoad];
    //根视图导航栏左侧和右侧的两个按钮
    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;

    //自定义从下一个视图左上角，“返回”根视图的按钮
    UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"后退" style:UIBarButtonItemStyleDone target:nil action:nil];
    self.navigationItem.backBarButtonItem=backButton;
    
    //自定义根视图下方的工具条，可进一步绑定各个按钮的处理函数；只对当前视图有效，切换到其他视图时为空白
    [self.navigationController  setToolbarHidden:NO animated:YES];
    UIBarButtonItem *one = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:nil action:nil];
    UIBarButtonItem *two = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemBookmarks target:nil action:nil];
    UIBarButtonItem *three = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:nil action:nil];
    UIBarButtonItem *four = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit target:nil action:nil];
    UIBarButtonItem *flexItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
    [self setToolbarItems:[NSArray arrayWithObjects:flexItem, one, flexItem, two, flexItem, three, flexItem, four, flexItem, nil]];
    
}

-(void)selectLeftAction:(id)sender
{
    UIAlertView *alter = [[UIAlertView alloc] initWithTitle:@"提示" message:@"你点击了导航栏左按钮" delegate:self  cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
    [alter show];
}

-(void)selectRightAction:(id)sender
{
    VCSecondView *vcSecondView;
    vcSecondView =[self.storyboard instantiateViewControllerWithIdentifier: @"second_view"];
    [self.navigationController pushViewController:vcSecondView animated:YES];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    //自定义在导航条显示的对第二个视图对描述；
    //UINavigationController的title可以用别的view替代，比如用UIButton UILable等，此处使用uibutton
    UIButton *button = [UIButton buttonWithType: UIButtonTypeRoundedRect];
    [button setTitle: @"自定义title" forState: UIControlStateNormal];
    [button sizeToFit];
    self.navigationItem.titleView = button;
    
    //导航栏右侧按钮
    UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(selectRightAction:)];
    self.navigationItem.rightBarButtonItem = rightButton;
    
    //自定义从下一个视图左上角，“返回”本视图的按钮
    UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"后退" style:UIBarButtonItemStyleDone target:nil action:nil];
    self.navigationItem.backBarButtonItem=backButton;
}

-(void)selectRightAction:(id)sender
{ 
    VCThirdView *vcThirdView;
    vcThirdView =[self.storyboard instantiateViewControllerWithIdentifier: @"third_view"];
    [self.navigationController pushViewController:vcThirdView animated:YES];
}

- (void)viewDidLoad
{
  。。。
  　NSArray *array = [NSArray arrayWithObjects:@"分割a",@"分割b", nil];
    UISegmentedControl *segmentedController = [[UISegmentedControl alloc] initWithItems:array];
    segmentedController.segmentedControlStyle = UISegmentedControlSegmentCenter;
    
    [segmentedController addTarget:self action:@selector(segmentAction:) forControlEvents:UIControlEventValueChanged];
    self.navigationItem.titleView = segmentedController;  
  。。。  
}

-(void)segmentAction:(id)sender
{
     switch ([sender selectedSegmentIndex]) {
         case 0:
         {
            UIAlertView *alter = [[UIAlertView alloc] initWithTitle:@"提示" message:@"你点击了分割a" delegate:self  cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
            [alter show];
         }
             break;
         case 1:
         {
             UIAlertView *alter = [[UIAlertView alloc] initWithTitle:@"提示" message:@"你点击了分割b" delegate:self  cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
             [alter show];
         }
             break;
 
         default:
             break;
     }
}

#import <UIKit/UIKit.h>

@interface VCSecondView : UIViewController
{
    UIToolbar *toolBar;
}
@end

　　UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemSearch target:self action:nil/*@selector(gotoThridView:)*/];
    toolBar = [[UIToolbar alloc] initWithFrame:CGRectMake(0.0, self.view.frame.size.height - toolBar.frame.size.height - 44.0, self.view.frame.size.width, 44.0)];
    [toolBar setBarStyle:UIBarStyleDefault];
    toolBar.autoresizingMask = UIViewAutoresizingFlexibleTopMargin;
    [toolBar setItems:[NSArray arrayWithObject:addButton]];
    [self.view addSubview:toolBar];