UINavigationBar 和 UINavigationItem的属性设置

 #import "RootViewController.h"

 @interface RootViewController ()

 @end

 @implementation RootViewController

 - (void)viewDidLoad {
     [super viewDidLoad];

     self.view.backgroundColor = [UIColor orangeColor];

     // 布局导航控制器
     [self initLayout];

 }

 - (void)initLayout {

     // 导航控制器的显示和隐藏
     self.navigationController.navigationBarHidden = NO;

 #pragma mark - UINavigationBar(导航条)
     // 设置导航条是否开启半透明效果
     // ios7.0之后，半透明效果默认是打开的，当半透明效果开启时，self.view以屏幕左上角为坐标原点，关闭时，导航条左下角为坐标原点。
     self.navigationController.navigationBar.translucent = NO;

 //    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
 //    view.backgroundColor = [UIColor cyanColor];
 //    [self.view addSubview:view];

     // 修改导航条颜色
     self.navigationController.navigationBar.barTintColor = [UIColor blackColor];
 //    self.navigationController.navigationBar.backgroundColor = [UIColor redColor];  // 修改背景颜色不能完成修改导航条颜色

     // 设置导航元素的颜色（item上按钮的颜色）
     self.navigationController.navigationBar.tintColor = [UIColor whiteColor];

     // 导航栏样式
     self.navigationController.navigationBar.barStyle = UIBarStyleBlack;  // 系统只有两种样式

     // 设置导航条标题
     self.title = @"根视图";

 #pragma mark - navigationTtem属性
     self.navigationItem.title = @"根视图";   // 也可以设置导航条标题

     // 左按钮
     self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"左按钮" style:UIBarButtonItemStylePlain target:self action:@selector(leftItemAction:)];

     // 右按钮
 //    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:@selector(rightItemClick:)];

 //    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"222.png"] style:UIBarButtonItemStylePlain target:self action:@selector(rightItemClick:)];

     // 某一边添加多个按钮，可以用rightBarButtonItems来添加多个，先创建多个按钮，再用数组的形式添加
     UIBarButtonItem *item1 = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(rightItemClick:)];
     UIBarButtonItem *item2 = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemBookmarks target:self action:@selector(rightItemClick:)];

     self.navigationItem.rightBarButtonItems = @[item1, item2];

     // 标题视图
     UISegmentedControl *segment = [[UISegmentedControl alloc] initWithItems:@[@"卫庄", @"盖聂"]];
     //segment.frame = CGRectMake(0, 0, 100, 30);  // 位置是固定的，设置frame并没有用
     // 修改标题视图
     self.navigationItem.titleView = segment;

 }

 // 实现方法
 - (void)leftItemAction:(UIBarButtonItem *)sender {

     NSLog(@"左按钮");
 }

 - (void)rightItemClick:(UIBarButtonItem *)sender {

     NSLog(@"右按钮");
 }