Ios Obj-C：如何修复PageViewController、PageController和2个按钮的约束

我按照此链接创建了带有“PageControl”的“PageViewController”，而不是在页面控件底部添加按钮。我想在页面控件的左侧和右侧添加两个按钮

问题 我设法用下面的代码添加了按钮，但约束已取消。我想尝试在故事板上设置，但不确定应该在哪里设置。请帮忙

@implementation RootViewController


- (void)viewDidLoad
{
    [super viewDidLoad];

    _pageTitles = @[@"", @"", @""];
    _pageImages = @[@"4.png", @"5.png", @"4.png"];

    // Create page view controller
    self.pageViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"PageViewController"];
    self.pageViewController.dataSource = self;

    PageContentViewController *startingViewController = [self viewControllerAtIndex:0];
    NSArray *viewControllers = @[startingViewController];
    [self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];

    // Change the size of page view controller
    self.pageViewController.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);

    btnLogin = [[UIButton alloc]initWithFrame:CGRectMake(0,self.view.frame.size.height-30, self.view.frame.size.width/4, 20)];

    btnLogin.backgroundColor = [UIColor colorWithRed:19.0f/255.0f green:147/255.0f blue:182.0f/255.0f alpha:1.0];//%%% buttoncolors
    [btnLogin setTitle:@"LOGIN" forState:UIControlStateNormal];
    [btnLogin addTarget:self action:@selector(btnLoginClicked:) forControlEvents:UIControlEventTouchUpInside];

    btnRegister = [[UIButton alloc]initWithFrame:CGRectMake(self.view.frame.size.width-((self.view.frame.size.width/4)),self.view.frame.size.height-30, self.view.frame.size.width/4, 20)];

    btnRegister.backgroundColor = [UIColor colorWithRed:19.0f/255.0f green:147/255.0f blue:182.0f/255.0f alpha:1.0];//%%% buttoncolors
    [btnRegister setTitle:@"REGISTER" forState:UIControlStateNormal];
    [btnRegister addTarget:self action:@selector(btnRegisterClicked:) forControlEvents:UIControlEventTouchUpInside];

    [self addChildViewController:_pageViewController];
    [self.view addSubview:_pageViewController.view];
    [self.view addSubview:btnLogin];
    [self.view addSubview:btnRegister];

    [self.pageViewController didMoveToParentViewController:self];

}

Iphone 6还可以

Iphone XSMax不受约束

情节提要

通过OnkarK尝试以下解决方案

 UIWindow *window = UIApplication.sharedApplication.keyWindow;
 CGFloat bottomPadding = window.safeAreaInsets.bottom;

 // Change the size of page view controller
 self.pageViewController.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);

 btnLogin = [[UIButton alloc]initWithFrame:CGRectMake(0,self.view.frame.size.height-30-bottomPadding, self.view.frame.size.width/4, 20)];

**我得到了以下信息，但是如何消除空白呢**

谢谢@phani，这确实是一个约束问题，必须始终约束SuperView，希望将来能帮助别人

---

当你以编程方式添加按钮时，你需要在设置帧时考虑安全区域。试试这个：

UIWindow *window = UIApplication.sharedApplication.keyWindow;
CGFloat bottomPadding = window.safeAreaInsets.bottom;
btnLogin = [[UIButton alloc]initWithFrame:CGRectMake(0,self.view.frame.size.height-30-bottomPadding, self.view.frame.size.width/4, 20)];

---

有关更多详细信息，请检查安全区域布局的自动布局问题。检查是否为安全区域提供了底部约束。