IOS 导航控制器基本使用（UINavigationController代码创建方式）

 ● UINavigationController的使用步骤

➢ 初始化UINavigationController

➢ 设置UIWindow的rootViewController为UINavigationController

➢ 根据具体情况,通过push方法添加对应个数的子控制器 

UINavigationController的子控制器 

● UINavigationController以栈的形式保存子控制器

@property(nonatomic,copy) NSArray *viewControllers;

@property(nonatomic,readonly) NSArray *childViewControllers;

● 使用push方法能将某个控制器压入栈
- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated;

● 使用pop方法可以移除控制器

➢ 将栈顶的控制器移除

- (UIViewController *)popViewControllerAnimated:(BOOL)animated;

➢ 回到指定的子控制器

- (NSArray *)popToViewController:(UIViewController *)viewController animated:(BOOL)animated;

➢ 回到根控制器(栈底控制器)
- (NSArray *)popToRootViewControllerAnimated:(BOOL)animated; 

修改导航栏的内容

● 导航栏的内容由栈顶控制器的navigationItem属性决定

● UINavigationItem有以下属性影响着导航栏的内容
➢ 左上角的返回按钮
@property(nonatomic,retain) UIBarButtonItem *backBarButtonItem;

➢ 中间的标题视图

@property(nonatomic,retain) UIView *titleView;

➢ 中间的标题文字

@property(nonatomic,copy) NSString *title;

➢ 左上角的视图

@property(nonatomic,retain) UIBarButtonItem *leftBarButtonItem;

➢ UIBarButtonItem *rightBarButtonItem 右上角的视图

@property(nonatomic,retain) UIBarButtonItem *rightBarButtonItem;

初级方式 1

@implementation NJAppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];
    
    // 1.创建导航控制器
    UINavigationController *nav = [[UINavigationController alloc] init];
    // 2.设置导航控制器为window的根控制器
    self.window.rootViewController = nav;
    
    
    // 创建第一个控制器并添加到导航控制器中
    NJOneViewController  *one = [[NJOneViewController  alloc] init];
    [nav pushViewController:one animated:YES];
    
    
    
    /*
    // 3.添加子控制器到导航控制器中
    // 创建一些子控制器
    UIViewController *vc1 = [[UIViewController alloc] init];
    vc1.view.backgroundColor   = [UIColor redColor];
    
    UIViewController *vc2 = [[UIViewController alloc] init];
    vc2.view.backgroundColor   = [UIColor greenColor];
    
    UIViewController *vc3 = [[UIViewController alloc] init];
    vc3.view.backgroundColor   = [UIColor purpleColor];
    
    // 添加子控制器到导航控制器中
    [nav pushViewController:vc1 animated:YES];
    [nav pushViewController:vc2 animated:YES];
    [nav pushViewController:vc3 animated:YES];
     */
    
    
    [self.window makeKeyAndVisible];
    return YES;
}

@interface NJOneViewController ()
/**
 *  跳转到第二个控制器
 */
- (IBAction)jump2Two:(id)sender;

@end

@implementation NJOneViewController

- (IBAction)jump2Two:(id)sender {
    
    // 1.创建第二个控制器
    NJTwoViewController *two = [[NJTwoViewController alloc] init];
    // 2.将第二个控制器添加到导航控制器中
    // 只要当前控制器是导航控制器的子控制器,就快要通过该属性直接获取到当前控制器所在的导航控制器
    [self.navigationController pushViewController:two animated:YES];
}

中级方式

@implementation NJAppDelegate

// 应用程序启动完毕即会调用
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];
    
    // 1.创建导航控制器
     NJOneViewController  *one = [[NJOneViewController  alloc] init];
    UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:one];
    
    // 2.设置导航控制器为window的根控制器
    self.window.rootViewController = nav;

    
    
    // 创建第一个控制器并添加到导航控制器中
    // NJOneViewController  *one = [[NJOneViewController  alloc] init];
    // 第一种
    // [nav pushViewController:one animated:YES];
    
    // 导航控制器的栈
//    nav.viewControllers; == nav.childViewControllers;
    //  第二种
//    [nav addChildViewController:one];
    
    // 第三种
//    nav.viewControllers = @[one];
    
    // 注意该属性是只读的
//    nav.childViewControllers = @[one];
    
    
    
//    NSLog(@"%d - %d", nav.viewControllers.count, nav.childViewControllers.count);
    
    // 获取栈顶的控制器
//    NSLog(@"%@", nav.topViewController);
    
    // 1.取出导航控制器的导航条


    [self.window makeKeyAndVisible];
    
    NSLog(@"didFinishLaunchingWithOptions");
    return YES;
}

// 应用程序获取焦点(代表着可以和用户交互)
- (void)applicationDidBecomeActive:(UIApplication *)application
{
    NSLog(@"applicationDidBecomeActive");
    
    
    UINavigationController *nav =  (UINavigationController *)self.window.rootViewController;
    UINavigationBar *bar =  nav.navigationBar;
//    NSLog(@"%@", NSStringFromCGRect(bar.frame));
    
    NSString *str =  [self digView:self.window];
    [str writeToFile:@"/Users/apple/Desktop/ios6.xml" atomically:YES];
    
}

/**
 *  返回传入veiw的所有层级结构
 *
 *  @param view 需要获取层级结构的view
 *
 *  @return 字符串
 */
- (NSString *)digView:(UIView *)view
{
    if ([view isKindOfClass:[UITableViewCell class]]) return @"";
    // 1.初始化
    NSMutableString *xml = [NSMutableString string];
    
    // 2.标签开头
    [xml appendFormat:@"<%@ frame="%@"", view.class, NSStringFromCGRect(view.frame)];
    if (!CGPointEqualToPoint(view.bounds.origin, CGPointZero)) {
        [xml appendFormat:@" bounds="%@"", NSStringFromCGRect(view.bounds)];
    }
    
    if ([view isKindOfClass:[UIScrollView class]]) {
        UIScrollView *scroll = (UIScrollView *)view;
        if (!UIEdgeInsetsEqualToEdgeInsets(UIEdgeInsetsZero, scroll.contentInset)) {
            [xml appendFormat:@" contentInset="%@"", NSStringFromUIEdgeInsets(scroll.contentInset)];
        }
    }
    
    // 3.判断是否要结束
    if (view.subviews.count == 0) {
        [xml appendString:@" />"];
        return xml;
    } else {
        [xml appendString:@">"];
    }
    
    // 4.遍历所有的子控件
    for (UIView *child in view.subviews) {
        NSString *childXml = [self digView:child];
        [xml appendString:childXml];
    }
    
    // 5.标签结尾
    [xml appendFormat:@"</%@>", view.class];
    
    return xml;
}

/**
 *  跳转到第二个控制器
 */
- (IBAction)jump2Two:(id)sender;

@end

@implementation NJOneViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    // 控制当前控制器对应的导航条显示的内容
    self.navigationItem.title = @"第一个控制器7788";
    
    // 给导航条添加一个按钮
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCamera target:nil action:nil];
    
    // self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemTrash target:nil action:nil];
    
   UIBarButtonItem *item0 =[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemTrash target:nil action:nil];
    
    UIBarButtonItem *item1 =[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:nil action:nil];
    
    self.navigationItem.rightBarButtonItems = @[item0, item1];

    
    // 修改返回按钮显示的内容
    self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"返回" style:UIBarButtonItemStylePlain target:nil action:nil];
    
    
}

- (IBAction)jump2Two:(id)sender {
    
    // 1.创建第二个控制器
    NJTwoViewController *two = [[NJTwoViewController alloc] init];
    // 2.将第二个控制器添加到导航控制器中
    // 只要当前控制器是导航控制器的子控制器,就快要通过该属性直接获取到当前控制器所在的导航控制器
    [self.navigationController pushViewController:two animated:YES];
}