UISB 导航控制器切换

scenedelegate.m

#import "SceneDelegate.h"
#import "VCRoot.h"
@interface SceneDelegate ()

@end

@implementation SceneDelegate


- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions {
    self.window = [[UIWindow alloc] initWithWindowScene:(UIWindowScene *)scene];
    self.window.frame = CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height);
    self.window.rootViewController=[[UINavigationController alloc]initWithRootViewController:[[VCRoot alloc]init]];
    
    [self.window makeKeyAndVisible];
    
    
    
}

VCRoot.m

#import "VCRoot.h"
#import "VCSecond.h"
@interface VCRoot ()

@end

@implementation VCRoot

- (void)viewDidLoad {
    [super viewDidLoad];
    //设置导航栏透明度
    self.navigationController.navigationBar.translucent=NO;
    
    self.navigationController.navigationBar.barStyle=UIBarStyleDefault;
    
    self.title=@"根视图";
    
    UIBarButtonItem* next = [[UIBarButtonItem alloc] initWithTitle:@"下一页" style:UIBarButtonItemStyleDone target:self action:@selector(preeNext)];
    
    
    
    self.navigationItem.rightBarButtonItem=next;
    
   
    
}

-(void)preeNext
{
    //创建一个新的导航控制器
    
    VCSecond* vcSecond= [[VCSecond alloc]init];
    //使用当前视图控制器的导航对象
    [self.navigationController pushViewController:vcSecond animated:YES];
    
    
    
    
    
}

@end

VCSecond.m

#import "VCSecond.h"
#import "VCThird.h"
@interface VCSecond ()

@end

@implementation VCSecond

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor=[UIColor greenColor];
    self.title=@"视图二";
    UIBarButtonItem* btnNext=[[UIBarButtonItem alloc]initWithTitle:@"第三级" style:UIBarButtonItemStyleDone target:self action:@selector(pressNext)];
    
    self.navigationItem.rightBarButtonItem=btnNext;
    
    
}

-(void)pressNext
{
    VCThird* vcThired=[[VCThird alloc]init];
    
    [self.navigationController pushViewController:vcThired animated:YES];
    
    
}

VCThird.m

#import "VCThird.h"

@interface VCThird ()

@end

@implementation VCThird

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor=[UIColor redColor];
    self.title=@"视图三";
    UIBarButtonItem* btnleft = [[UIBarButtonItem alloc] initWithTitle:@"返回" style:UIBarButtonItemStyleDone target:self action:@selector(pressroot)];
    
    self.navigationItem.leftBarButtonItem=btnleft;
    
    
}


-(void)pressroot
{
    [self.navigationController popToRootViewControllerAnimated:YES];
    
}

-(void)pressback
{
    //将当前视图控制器弹出返回上一级界面
    [self.navigationController popViewControllerAnimated:YES];
}