iOS

Question

我有一个带有默认状态栏的 CollectionViewController，它全部嵌入到 NavigationController 中。

我正在尝试重现一种效果，在该效果中，我将一个视图锚定在屏幕顶部，因为我的 navController 是完全透明的，我的状态栏也是透明的，但是不知何故，当我将我的视图锚定到topAnchor 它保持与 NavigationController bottomAnchor 的剪辑，因为它 'thinks' 屏幕的顶部是 navController 的底部。

在将视图锚定到顶部后，我设法绕过了它，我给它一个负的 topPadding，它现在是我想要的位置。

我知道有一种方法可以将布局扩展到顶部屏幕，但我想不通。

你能给我一个提示吗？

我正在尝试这个：

我明白了：

白色的space是状态栏高度+NavigationController高度

谢谢

Answer 1

如果您不希望 ViewControllers 内容视图在 top/bottom 栏下延伸，您可以使用 Interface Builder 中的“在顶部 Bars/Under 底部栏下延伸边缘”设置。

试试这个

目标 C:

self.edgesForExtendedLayout = UIRectEdgeNone;

Swift3:

self.edgesForExtendedLayout = []

希望对您有所帮助:)

Answer 2

好吧，这会将我的 UIImageView 固定到屏幕顶部...在导航栏和状态栏下方。与集合视图应该没有什么不同：

NSLayoutConstraint *top = [NSLayoutConstraint
                           constraintWithItem:imageView
                           attribute:NSLayoutAttributeTop
                           relatedBy:NSLayoutRelationEqual
                           toItem:self.view
                           attribute:NSLayoutAttributeTop
                           multiplier:1
                           constant:0];

编辑：抱歉，我正在做一个 Obj-C 项目...这里是 Swift:

    let img = UIImage(named: "Man")
    let imageView = UIImageView(image: img)
    imageView.translatesAutoresizingMaskIntoConstraints = false

    self.view.addSubview(imageView)

    imageView.widthAnchor.constraint(equalToConstant: 200.0).isActive = true
    imageView.heightAnchor.constraint(equalToConstant: 200.0).isActive = true

    imageView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true

    imageView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true

并且...这里还有一个集合视图（很难用普通的屏幕截图来分辨）：

    self.view.backgroundColor = .white

    let img = UIImage(named: "Man")
    let imageView = UIImageView(image: img)
    imageView.translatesAutoresizingMaskIntoConstraints = false

    self.view.addSubview(imageView)

    imageView.widthAnchor.constraint(equalToConstant: 200.0).isActive = true
    imageView.heightAnchor.constraint(equalToConstant: 200.0).isActive = true

    imageView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true

    imageView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true

    let layout = UICollectionViewFlowLayout()
    let cv = UICollectionView(frame: CGRect.zero, collectionViewLayout: layout)
    cv.backgroundColor = .clear

    cv.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "defaultCell")
    cv.dataSource = self

    cv.translatesAutoresizingMaskIntoConstraints = false
    self.view.addSubview(cv)

    cv.widthAnchor.constraint(equalTo: self.view.widthAnchor, multiplier: 0.9).isActive = true
    cv.heightAnchor.constraint(equalToConstant: 300.0).isActive = true

    cv.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true

    cv.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true

Answer 3

class DetailsPage : UIViewController {

    let topView:UIView = UIView()
    let topSliderImage:UIImageView = UIImageView()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        setUI()
    }

    override func viewWillAppear(_ animated: Bool) { 
        navigationController?.navigationBar.isTranslucent = true
        navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
        navigationController?.navigationBar.shadowImage = UIImage() 
    }

    func setUI(){

        self.view.addSubview(topSliderImage)
        topSliderImage.image = UIImage(named: "img-1")
        topSliderImage.contentMode = .scaleAspectFit
        topSliderImage.translatesAutoresizingMaskIntoConstraints = false
        topSliderImage.topAnchor.constraint(equalTo: view.topAnchor, constant: 0).isActive = true
        topSliderImage.heightAnchor.constraint(equalToConstant: 300).isActive = true
        topSliderImage.widthAnchor.constraint(equalToConstant: view.frame.width).isActive = true
    }
}

iOS - 将视图锚定到屏幕顶部，状态栏后面

iOS - anchor view to the top of the screen, behind status bar

uinavigationcontroller

nslayoutconstraint

swift3

nslayoutanchor