Question

我已经可以使用ff代码将背景图像添加到导航栏，但图像会被拉伸。有什么方法可以不被拉伸吗？

 self.navigationController?.navigationBar.setBackgroundImage(UIImage(named: "BG.jpg"), for: .default)

Answer 1

你可以试试这个，

var mylist = [{"email":null,"school":"schoolA","courses":[{"name":"ABC","type":"chemistry"},{"name":"XYZ","type":"math"}]},{"email":null,"school":"schoolB"}]

const course = mylist.reduce((r, {courses}) => {
  if (courses && !r) {
    const course = courses.find(({type}) => type == 'chemistry');
    if (course) r = course.name;
  }
  return r;
}, null)

console.log(course)

尝试代码中的其他选项。

<强>更新

您甚至可以尝试UINavigationBar.appearance().setBackgroundImage(UIImage(named: "BG.jpg")!.resizableImage(withCapInsets: UIEdgeInsets.zero, resizingMode: .stretch), for: .default)

的以下类别

UINavigationBar

以上代码可能会因您的最终要求而异。

Answer 2

///此属性将图像设置为导航栏

public var navigationBarImage: UIImage? {
    get {
        return (navigationItem.titleView as? UIImageView)?.image
    } set {
        if newValue != nil {
            let imageView = UIImageView(image: newValue)
            imageView.contentMode = .scaleAspectFit
            navigationItem.titleView = imageView
        } else {
            navigationItem.titleView = nil
        }
    }
}

Answer 3

对于所有图像，您可以设置内容模式=

.scaleToFill (UIViewContentModeScaleToFill)
.scaleAspectFit (UIViewContentModeScaleAspectFit)
.scaleAspectFill (UIViewContentModeScaleAspectFill)

如果您不想看到超出界限的内容，您需要记住在包含的超级视图上将clipsToBounds设置为true

View.clipsToBounds = true

Swift ios如何设置导航栏图像不拉伸

3 个答案: