ios中模态弹窗用法及UINavigationController基本用法

- (void)viewDidLoad {
    [super viewDidLoad];
    //点击按钮跳转
    loginViewController *vc=[[loginViewController alloc] init];
    UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:vc];
    [self presentViewController:nav animated:YES completion:nil];
}

@implementation loginViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor whiteColor];
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"取消" style:UIBarButtonItemStyleDone target:self action:@selector(cancel)];
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"注册" style:UIBarButtonItemStyleDone target:self action:@selector(regist)];
    self.title = @"登陆";
}
//取消
- (void)cancel
{
    [self dismissModalViewControllerAnimated:YES];
}
//注册
-(void)regist
{
    
}
@end

@implementation MJOneViewController
- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.navigationItem.title = @"第1个控制器";
    
    // 修改下一个界面返回按钮的文字
    self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"返回" style:UIBarButtonItemStyleDone target:nil action:nil];
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCamera target:nil action:nil];
}

- (IBAction)jumpTwo {
    // 调到第2个控制器
    MJTwoViewController *two = [[MJTwoViewController alloc] init];
    //[self.navigationController presentModalViewController:two animated:YES];
    [self.navigationController pushViewController:two animated:YES];
}
@end

@implementation MJTwoViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.navigationItem.titleView = [UIButton buttonWithType:UIButtonTypeContactAdd];
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemTrash target:nil action:nil];
    self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc] initWithTitle:@"哈哈" style:UIBarButtonItemStyleDone target:self action:nil];
}

- (IBAction)jumpThree {
    MJThreeViewController *three = [[MJThreeViewController alloc] init];
    [self.navigationController pushViewController:three animated:YES];
}
@end