Objective C如何在从第一个VC移动到第二个时停止无限循环

Question

我正在尝试构建一个启动画面，所以我希望第一个视图控制器在 3.0 秒后自动移动到第二个 ViwController 我尝试了下面的方法但是一个无限循环已经开始我应该做什么，我应该如何停止第二个视图控制器。

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    NSLog(@"%p", self);
    NSLog(@"1st Controller");

    [self.navigationController setNavigationBarHidden:YES animated:YES];
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{


        [self loadingNextView];
      });

}

    - (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}
- (void)loadingNextView{

    LoginViewController *viewController = [self.storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"];
    [self.navigationController pushViewController:viewController animated:true];
}
//LoginViewController.h
@interface LoginViewController : ViewController

@end
//LoginViewController.m

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    NSLog(@"2nd View Controller");
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

三秒钟后看看循环是如何工作的。

Answer 1

你为什么不使用NSTimer 类。只需创建一个 10 秒的计时器，当 10 秒过去的计时器将触发该事件时，您可以移动到另一个 controller。像这样创建一个计时器

[NSTimer scheduledTimerWithTimeInterval:10.0
        target:self
        selector:@selector(targetMethod:)
        userInfo:nil
        repeats:NO];



    - (void)targetMethod:(NSTimer*)timer {
        [self loadingNextView];
    }

Answer 2

很简单，可以在vc1中添加一个属性判断是否是先来的：

结果：

适合 VC：

#import "ViewController.h"
#import "LoginViewController.h"

@interface ViewController ()

@property(nonatomic, assign) BOOL isFirstTime;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    _isFirstTime = YES;
}

- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
/*  [self performSelector:@selector(loadingNextView)
 withObject:nil afterDelay:1.0f]; */

    if (_isFirstTime == NO) {

        return;
    }

    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{


    [self loadingNextView];
    _isFirstTime = NO;
    });

}
- (void)loadingNextView{

    LoginViewController *viewController = [self.storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"];
    [self.navigationController pushViewController:viewController animated:true];
}

Answer 3

试试这个

[NSTimer scheduledTimerWithTimeInterval:1.0 repeats:false block:^(NSTimer * _Nonnull timer) {
    [self loadingNextView];
}];

所以一点建议，您应该考虑呈现一个 loginViewController，而不是将其推送到 NavigationController 堆栈。如果你按下它，如果你不想让用户回到另一个 ViewController，你必须删除后退按钮。如果您提供它，您可以确保用户在不输入登录数据的情况下无法返回 firstVc。

在第二个 Vc 中你可以关闭 Vc 或者你可以展示一个新的 ViewController。

[self presentViewController:vc animated:YES completion:nil];

Answer 4

您可以通过使用它来实现您的目标。

#import "DrawingViewController.h"
#import "SecondViewController.h"

@interface DrawingViewController ()

@end

@implementation DrawingViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    [button removeFromSuperview];

    [NSTimer scheduledTimerWithTimeInterval:3.0 target:self selector:@selector(target:) userInfo:nil repeats:NO];

}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)target:(NSTimer*)timer {

    SecondViewController* controller = [self.storyboard instantiateViewControllerWithIdentifier:@"SecondViewController"];
    [self.navigationController pushViewController:controller animated:YES];
}

Answer 5

终于找到答案了。

    #import "ViewController.h"
    - (void)viewDidLoad {
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.
        NSLog(@"%p", self);
        [self.navigationController setNavigationBarHidden:YES animated:YES];
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 3 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{

            NSLog(@"1st controller");
            [self loadingNextView];
        });

    }


    - (void)didReceiveMemoryWarning {
        [super didReceiveMemoryWarning];
        // Dispose of any resources that can be recreated.
    }

    - (void)loadingNextView{

        UIViewController *viewController = [self.storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"];
        [self.navigationController pushViewController:viewController animated:true];
    }
//LoginViewController.h
#import "ViewController.h"

@interface LoginViewController : UIViewController

@end
//LoginViewController.m
#import "LoginViewController.h"

@interface LoginViewController ()

@end

@implementation LoginViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    NSLog(@"2nd View Controller");
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}