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1,使用图像控件显示图片 let imageView = UIImageView(image:UIImage(named:"image1")) imageView.frame = CGRect(x:10, y:30, width:300, height:150) self.view.addSubview(imageView) 2,改变图片 imageView.image = UIImage(named:"icon2") 3,从文件目录中获取图片 let path = Bundle.main.path(forResource: "ball", ofType: "png") let newImage = UIImage(contentsOfFile: path!) let imageView = UIImageView(image:newImage) self.view.addSubview(imageView) 4,从网络地址获取图片 //定义URL对象 let url = URL(string: "网络图片的URL地址") //从网络获取数据流 let data = try! Data(contentsOf: url!) //通过数据流初始化图片 let newImage = UIImage(data: data) let imageView = UIImageView(image:newImage); self.view.addSubview(imageView) 5,使用图像控件实现动画播放 UIImageView 中提供了存储多张图片来创建动画的功能,具体做法是,在 animationImages 属性中设置一个图片数组,然后使用 startAnimating 方法开始动画,最后用 stopAnimating 方法停止动画。同时,使用 animationDuration 属性中可以设置动画每帧切换的速度(秒)。 import UIKit class ViewController: UIViewController { var imageView:UIImageView! override func viewDidLoad() { super.viewDidLoad() imageView = UIImageView() imageView.frame=CGRect(x:20, y:20, width:100, height:100) //设置动画图片 imageView.animationImages = [UIImage(named:"icon1")!,UIImage(named:"icon2")!] //设置每隔0.5秒变化一次 imageView.animationDuration=0.5 imageView.startAnimating() self.view.addSubview(imageView) } override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) imageView.startAnimating() } override func viewWillDisappear(_ animated: Bool) { super.viewWillAppear(animated) imageView.stopAnimating() } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() } } 6,保持图片比例 默认 UIImageView 会拉伸图片使其占满整个 UIImageView,如果不想让图片变形,可以将 ContentMode 设置为 Aspect Fit。 imageView.contentMode = .scaleAspectFit contentMode可设置: case scaleToFill case scaleAspectFit // contents scaled to fit with fixed aspect. remainder is transparent case scaleAspectFill // contents scaled to fill with fixed aspect. some portion of content may be clipped. case redraw // redraw on bounds change (calls -setNeedsDisplay) case center // contents remain same size. positioned adjusted. case top case bottom case left case right case topLeft case topRight case bottomLeft case bottomRight 图片发自简书App |
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