我希望能够通过使用标志图像作为导航栏标题来自定义我的应用程序的外观,而不是使用纯文本。当我使用这段代码时:
let logo = UIImage(named: "logo.png")
self.navigationItem.titleView = logo;
我收到了错误信息“UIImage无法转换为UIView”。我该如何正确处理?
let logo = UIImage(named: "logo.png")
self.navigationItem.titleView = logo;
我收到了错误信息“UIImage无法转换为UIView”。我该如何正确处理?
将它放进一个UIImageView
中
let logo = UIImage(named: "logo.png")
let imageView = UIImageView(image:logo)
self.navigationItem.titleView = imageView
UINavigationController.viewDidLoad
(我为导航控制器实现的类)中,它不起作用,但如果我将其添加到ViewController
中,则可以正常工作。但是我想保持这段代码分离(所以在扩展UINavigationController的类中)。这可能吗? - PatriksviewDidLoad
方法,而不是在导航控制器本身中使用。 - Martin Marconcini我使用这个,它在iOS 8上有效。
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let image = UIImage(named: "YOURIMAGE")
navigationItem.titleView = UIImageView(image: image)
}
以下是使用CGRect的示例。
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 38, height: 38))
imageView.contentMode = .ScaleAspectFit
let image = UIImage(named: "YOURIMAGE")
imageView.image = image
navigationItem.titleView = imageView
}
希望这能有所帮助。
对于Swift 4,您可以调整imageView的大小
let logoContainer = UIView(frame: CGRect(x: 0, y: 0, width: 270, height: 30))
let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 270, height: 30))
imageView.contentMode = .scaleAspectFit
let image = UIImage(named: "your_image")
imageView.image = image
logoContainer.addSubview(imageView)
navigationItem.titleView = logoContainer
我尝试了@Jack在上面给出的答案,标志确实出现了,但是图像占用了整个导航栏。我想让它适合。
Swift 4,Xcode 9.2
1.为导航控制器分配值UIImage。通过将框架和图像大小相除来调整大小。
func addNavBarImage() {
let navController = navigationController!
let image = UIImage(named: "logo-signIn6.png") //Your logo url here
let imageView = UIImageView(image: image)
let bannerWidth = navController.navigationBar.frame.size.width
let bannerHeight = navController.navigationBar.frame.size.height
let bannerX = bannerWidth / 2 - (image?.size.width)! / 2
let bannerY = bannerHeight / 2 - (image?.size.height)! / 2
imageView.frame = CGRect(x: bannerX, y: bannerY, width: bannerWidth, height: bannerHeight)
imageView.contentMode = .scaleAspectFit
navigationItem.titleView = imageView
}
将该功能添加在 viewDidLoad()
函数下方。 addNavBarImage()
关于图像资产的注意事项。上传之前,我进行了额外的边距调整而不是裁剪边缘。
最终结果:
您可以使用自定义的UINavigationItem,只需要在Main.storyboard中将“Navigation Item”更改为YourCustomClass。
在Swift 3中
class FixedImageNavigationItem: UINavigationItem {
private let fixedImage : UIImage = UIImage(named: "your-header-logo.png")!
private let imageView : UIImageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 50, height: 37.5))
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
imageView.contentMode = .scaleAspectFit
imageView.image = fixedImage
self.titleView = imageView
}
}
这个方法在2015年9月对我有效 - 希望能帮助到某位需要的人。
// 1
var nav = self.navigationController?.navigationBar
// 2 set the style
nav?.barStyle = UIBarStyle.Black
nav?.tintColor = UIColor.yellowColor()
// 3
let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 40, height: 40))
imageView.contentMode = .ScaleAspectFit
// 4
let image = UIImage(named: "logo.png")
imageView.image = image
// 5
navigationItem.titleView = imageView
navigationItem.titleView = imageView
而是使用
self.navBar.topItem?.titleView = imageView
这里有详细的说明: - knopch1425override func viewDidLoad() {
super.viewDidLoad()
//Sets the navigation title with text and image
self.navigationItem.titleView = navTitleWithImageAndText(titleText: "Dean Stanley", imageName: "online")
}
func navTitleWithImageAndText(titleText: String, imageName: String) -> UIView {
// Creates a new UIView
let titleView = UIView()
// Creates a new text label
let label = UILabel()
label.text = titleText
label.sizeToFit()
label.center = titleView.center
label.textAlignment = NSTextAlignment.center
// Creates the image view
let image = UIImageView()
image.image = UIImage(named: imageName)
// Maintains the image's aspect ratio:
let imageAspect = image.image!.size.width / image.image!.size.height
// Sets the image frame so that it's immediately before the text:
let imageX = label.frame.origin.x - label.frame.size.height * imageAspect
let imageY = label.frame.origin.y
let imageWidth = label.frame.size.height * imageAspect
let imageHeight = label.frame.size.height
image.frame = CGRect(x: imageX, y: imageY, width: imageWidth, height: imageHeight)
image.contentMode = UIView.ContentMode.scaleAspectFit
// Adds both the label and image view to the titleView
titleView.addSubview(label)
titleView.addSubview(image)
// Sets the titleView frame to fit within the UINavigation Title
titleView.sizeToFit()
return titleView
}
我已经为iOS 10和iOS 11编写了以下内容,并且它对我有效:
extension UINavigationBar {
func setupNavigationBar() {
let titleImageWidth = frame.size.width * 0.32
let titleImageHeight = frame.size.height * 0.64
var navigationBarIconimageView = UIImageView()
if #available(iOS 11.0, *) {
navigationBarIconimageView.widthAnchor.constraint(equalToConstant: titleImageWidth).isActive = true
navigationBarIconimageView.heightAnchor.constraint(equalToConstant: titleImageHeight).isActive = true
} else {
navigationBarIconimageView = UIImageView(frame: CGRect(x: 0, y: 0, width: titleImageWidth, height: titleImageHeight))
}
navigationBarIconimageView.contentMode = .scaleAspectFit
navigationBarIconimageView.image = UIImage(named: "image")
topItem?.titleView = navigationBarIconimageView
}
}
Swift 5.1+,Xcode 13+
有时候如果你的图片分辨率很高,imageView 就会偏离中心位置,我建议使用这种方法:
lazy var navigationTitleImageView = UIImageView()
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.navigationTitleImageView.image = logo
self.navigationTitleImageView.contentMode = .scaleAspectFit
self.navigationTitleImageView.translatesAutoresizingMaskIntoConstraints = false
if let navC = self.navigationController{
navC.navigationBar.addSubview(self.navigationTitleImageView)
self.navigationTitleImageView.centerXAnchor.constraint(equalTo: navC.navigationBar.centerXAnchor).isActive = true
self.navigationTitleImageView.centerYAnchor.constraint(equalTo: navC.navigationBar.centerYAnchor, constant: 0).isActive = true
self.navigationTitleImageView.widthAnchor.constraint(equalTo: navC.navigationBar.widthAnchor, multiplier: 0.2).isActive = true
self.navigationTitleImageView.heightAnchor.constraint(equalTo: navC.navigationBar.widthAnchor, multiplier: 0.088).isActive = true
}
}
并且viewWillDisappear()
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
self.navigationTitleImageView.removeFromSuperview()
}
title
属性或此导航控制器的navigationItem.title
,那么该文本将出现在你添加的图像后面,而我们不希望发生这种情况。 - Rhenzclass CustomTitleNavigationController: UINavigationController {
override func viewDidLoad() {
super.viewDidLoad()
let logo = UIImage(named: "MyHeaderImage")
let imageView = UIImageView(image:logo)
imageView.contentMode = .scaleAspectFit
imageView.translatesAutoresizingMaskIntoConstraints = false
navigationBar.addSubview(imageView)
navigationBar.addConstraint (navigationBar.leftAnchor.constraint(equalTo: imageView.leftAnchor, constant: 0))
navigationBar.addConstraint (navigationBar.rightAnchor.constraint(equalTo: imageView.rightAnchor, constant: 0))
navigationBar.addConstraint (navigationBar.topAnchor.constraint(equalTo: imageView.topAnchor, constant: 0))
navigationBar.addConstraint (navigationBar.bottomAnchor.constraint(equalTo: imageView.bottomAnchor, constant: 0))
}