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**********创建UIIMageView
let imageView = UIImageView(image:UIImage(named:"image1"))
imageView.frame = CGRect(x:10, y:30, width:300, height:150)
self.view.addSubview(imageView)
****************设置图片image
imageView.image = UIImage(named:"icon2")
**************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)
*******************从网络地址获取图片
//定义URL对象
let url = URL(string: "http://******/l.png")
//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)
*******************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
self.view.addSubview(imageView)
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
imageView.startAnimating()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillAppear(animated)
imageView.stopAnimating()
}
}
**************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
==========================UIIMage
==========CIImage、CGImage、UIImage之间的相互转换
CIImage转UIImage
/// CIImage转UIImage相对简单，直接使用UIImage的初始化方法即可
func convertCIImageToUIImage(ciImage:CIImage) -> UIImage {
let uiImage = UIImage.init(ciImage: ciImage)
// 注意！！！这里的uiImage的uiImage.cgImage 是nil
let cgImage = uiImage.cgImage
// 注意！！！上面的cgImage是nil，原因如下，官方解释
// returns underlying CGImageRef or nil if CIImage based
return uiImage
}
CGImage转UIImage
// CGImage转UIImage相对简单，直接使用UIImage的初始化方法即可
// 原理同上
func convertCIImageToUIImage(cgImage:CGImage) -> UIImage {
let uiImage = UIImage.init(cgImage: cgImage)
// 注意！！！这里的uiImage的uiImage.ciImage 是nil
let ciImage = uiImage.ciImage
// 注意！！！上面的ciImage是nil，原因如下，官方解释
// returns underlying CIImage or nil if CGImageRef based
return uiImage
}
CGImage与CIImage互相转换
// MARK:- convert the CGImageToCIImage
/// convertCGImageToCIImage
///
/// - Parameter cgImage: input cgImage
/// - Returns: output CIImage
func convertCGImageToCIImage(cgImage:CGImage) -> CIImage{
return CIImage.init(cgImage: cgImage)
}
// MARK:- convert the CIImageToCGImage
/// convertCIImageToCGImage
///
/// - Parameter ciImage: input ciImage
/// - Returns: output CGImage
func convertCIImageToCGImage(ciImage:CIImage) -> CGImage{
let ciContext = CIContext.init()
let cgImage:CGImage = ciContext.createCGImage(ciImage, from: ciImage.extent)!
return cgImage
}
UIImage转为CGImage、CIImage
/// UIImage转为CIImage
/// UIImage转CIImage有时候不能直接采用uiImage.ciImage获取
/// 当uiImage.ciImage为nil的时候需要先通过uiImage.cgImage得到
/// cgImage, 然后通过convertCGImageToCIImage将cgImage装换为ciImage
func convertUIImageToCIImage(uiImage:UIImage) -> CIImage {
var ciImage = uiImage.ciImage
if ciImage == nil {
let cgImage = uiImage.cgImage
ciImage = self.convertCGImageToCIImage(cgImage: cgImage!)
}
return ciImage!
}
/// UIImage转为CGImage
/// UIImage转CGImage有时候不能直接采用uiImage.cgImage获取
/// 当uiImage.cgImage为nil的时候需要先通过uiImage.ciImage得到
/// ciImage, 然后通过convertCIImageToCGImage将ciImage装换为cgImage
func convertUIImageToCGImage(uiImage:UIImage) -> CGImage {
var cgImage = uiImage.cgImage
if cgImage == nil {
let ciImage = uiImage.ciImage
cgImage = self.convertCIImageToCGImage(ciImage: ciImage!)
}
return cgImage!
}
// 通过UIImage.init(named: "image.png") 得到的uiImage
// 默认是通过CGImageRef得到的因此uiImage的uiImage.ciImage为nil
let uiImage = UIImage.init(named: "image.png")
// cgImage有值
let cgImage = uiImage.cgImage
// ciImage为nil
let ciImage = uiImage.ciImage
UIImage转Data
// 只有当uiImage.cgImage有值的时候才可以使用UIImagePNGRepresentation(_ image: UIImage)
// 或者UIImageJPEGRepresentation(_ image: UIImage, _ compressionQuality: CGFloat)转换为Data
func convertUIImageToData(uiImage:UIImage) -> Data {
var data = UIImagePNGRepresentation(uiImage)
if data == nil {
let cgImage = self.convertUIImageToCGImage(uiImage: uiImage)
let uiImage_ = UIImage.init(cgImage: cgImage)
data = UIImagePNGRepresentation(uiImage_)
}
return data!
}
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