ios - 以编程方式添加 UINavigationBar 和状态栏

Question

我正在以编程方式创建一个 UINavigationBar，我希望它在状态栏下扩展。这是代码:

_baseView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height)];[_baseView setBackgroundColor:[UIColor redColor]];
self.view = _baseView;
        
_navigationBar = [[UINavigationBar alloc] init];
        
[_navigationBar setBarTintColor:[UIColor greenColor]];
[_navigationBar setBackgroundColor:[UIColor purpleColor]];
             
UINavigationItem* navigationItem = [[UINavigationItem alloc] initWithTitle:@"Title!"];
[_navigationBar setTitleTextAttributes:self.navigationController.navigationBar.titleTextAttributes];
[_navigationBar pushNavigationItem:navigationItem animated:NO];
        
[_navigationBar setTranslatesAutoresizingMaskIntoConstraints:NO];
        
[self.view addSubview:_navigationBar];
        
[_navigationBar.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor].active = YES;
[_navigationBar.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor].active = YES;
[_navigationBar.topAnchor constraintEqualToAnchor:self.view.topAnchor].active = YES;
[_navigationBar.heightAnchor constraintEqualToConstant:64].active = YES;

不幸的是，输出并不完全正确。正如您在下图中看到的，整个 UINavigationBar 的大小是正确的，紫色，但标题和其余部分的大小不同。
我在这里想念什么？

Answer 1

正如 azamsharp 指出的那样，一种可能的解决方案是嵌入 UINavigationController 中。

另一种方法如下。

使您的 ViewController 成为 UINavigationBarDelegate，在创建 UINavigationBar 时将 self 设置为委托(delegate)，然后实现 - (UIBarPosition)positionForBar:

样本:

- (void)viewDidLoad {
    [super viewDidLoad];

    _baseView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height)];
    [_baseView setBackgroundColor:[UIColor redColor]];
    self.view = _baseView;

    _navigationBar = [[UINavigationBar alloc] init];

    [_navigationBar setBarTintColor:[UIColor greenColor]];
    [_navigationBar setBackgroundColor:[UIColor purpleColor]];

    [_navigationBar setDelegate:self];

    UINavigationItem* navigationItem = [[UINavigationItem alloc] initWithTitle:@"Title!"];
    [_navigationBar setTitleTextAttributes:self.navigationController.navigationBar.titleTextAttributes];
    [_navigationBar pushNavigationItem:navigationItem animated:NO];

    [_navigationBar setTranslatesAutoresizingMaskIntoConstraints:NO];

    [self.view addSubview:_navigationBar];

    [_navigationBar.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor].active = YES;
    [_navigationBar.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor].active = YES;
    if (@available(iOS 11.0, *)) {
        [_navigationBar.topAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.topAnchor].active = YES;
    } else {
        [_navigationBar.topAnchor constraintEqualToAnchor:self.topLayoutGuide.bottomAnchor].active = YES;
    }
}

- (UIBarPosition)positionForBar:(id<UIBarPositioning>)bar {
    return UIBarPositionTopAttached;
}