屏幕全宽快速uiimage

let imageView = UIImageView(image: image!)
imageView.contentMode = .scaleAspectFill
imageView.frame = self.view.bounds
imageView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
self.view.addSubview(imageView)

你必须把你的 UIImageView 框出要填充的区域的大小。可以通过显式设置框架或使用自动布局(推荐)来完成此操作。

方法1:

let imageView = UIImageView(image: image!)
imageView.frame = self.view.frame;
imageView.contentMode = .scaleAspectFit
//Add Image to view
self.view.addSubview(imageView)

方法2:

let imageView = UIImageView(image: image!)
imageView.contentMode = .scaleAspectFit
//Add Image to view
self.view.addSubview(imageView)
self.view.translatesAutoresizingMaskIntoConstraints = false  

self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|-0-[subview]-0-|", options: .directionLeadingToTrailing, metrics: nil, views: ["subview": imageView]))
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-0-[subview]-0-|", options: .directionLeadingToTrailing, metrics: nil, views: ["subview": imageView]))

你想操纵 UIImageView 而不是ContentMode。

试试这个:

let imageView = UIImageView(image: image!)

imageView.frame = self.view.frame
imageView.contentMode = .scaleToFill

self.view.addSubview(imageView)