JKSwiftExtension，测试用例在 UIImageExtensionViewController.swift 里面
目录：
1、基本的扩展
2、UIColor 生成的图片 和 生成渐变色图片
3、图片的拉伸和缩放
4、UIImage 压缩相关
5、二维码的处理
6、gif 加载
一、基本的扩展
// MARK:- 一、基本的扩展
public extension UIImage {
// MARK: 1.1、设置图片的圆角
/// 设置图片的圆角
/// - Parameters:
/// - radius: 圆角大小 (默认:3.0,图片大小)
/// - corners: 切圆角的方式
/// - imageSize: 图片的大小
/// - Returns: 剪切后的图片
func isRoundCorner(radius: CGFloat = 3, byRoundingCorners corners: UIRectCorner = .allCorners, imageSize: CGSize?) -> UIImage? {
let weakSize = imageSize ?? size
let rect = CGRect(origin: CGPoint(x: 0, y: 0), size: weakSize)
// 开始图形上下文
UIGraphicsBeginImageContextWithOptions(weakSize, false, UIScreen.main.scale)
guard let contentRef: CGContext = UIGraphicsGetCurrentContext() else {
// 关闭上下文
UIGraphicsEndImageContext();
return nil
}
// 绘制路线
contentRef.addPath(UIBezierPath(roundedRect: rect,
byRoundingCorners: UIRectCorner.allCorners,
cornerRadii: CGSize(width: radius, height: radius)).cgPath)
// 裁剪
contentRef.clip()
// 将原图片画到图形上下文
draw(in: rect)
contentRef.drawPath(using: .fillStroke)
guard let output = UIGraphicsGetImageFromCurrentImageContext() else {
// 关闭上下文
UIGraphicsEndImageContext();
return nil
}
// 关闭上下文
UIGraphicsEndImageContext();
return output
}
// MARK: 1.2、设置圆形图片
/// 设置圆形图片
/// - Returns: 圆形图片
func isCircleImage() -> UIImage? {
return isRoundCorner(radius: (self.size.width < self.size.height ? self.size.width : self.size.height) / 2.0, byRoundingCorners: .allCorners, imageSize: self.size)
}
// MARK: 1.3、获取视频的第一帧
/// 获取视频的第一帧
/// - Parameters:
/// - videoUrl: 视频 url
/// - maximumSize: 图片的最大尺寸
/// - Returns: 视频的第一帧
static func getVideoFirstImage(videoUrl: String, maximumSize: CGSize = CGSize(width: 1000, height: 1000), closure: @escaping (UIImage?) -> Void) {
guard let url = URL(string: videoUrl) else {
closure(nil)
return
}
DispatchQueue.global().async {
let opts = [AVURLAssetPreferPreciseDurationAndTimingKey: false]
let avAsset = AVURLAsset(url: url, options: opts)
let generator = AVAssetImageGenerator(asset: avAsset)
generator.appliesPreferredTrackTransform = true
generator.maximumSize = maximumSize
var cgImage: CGImage? = nil
let time = CMTimeMake(value: 0, timescale: 600)
var actualTime : CMTime = CMTimeMake(value: 0, timescale: 0)
do {
try cgImage = generator.copyCGImage(at: time, actualTime: &actualTime)
} catch {
DispatchQueue.main.async {
closure(nil)
}
return
}
guard let image = cgImage else {
DispatchQueue.main.async {
closure(nil)
}
return
}
DispatchQueue.main.async {
closure(UIImage(cgImage: image))
}
}
}
// MARK: 1.4、layer 转 image
/// layer 转 image
/// - Parameters:
/// - layer: layer 对象
/// - scale: 缩放比例
/// - Returns: 返回转化后的 image
static func image(from layer: CALayer, scale: CGFloat = 0.0) -> UIImage? {
UIGraphicsBeginImageContextWithOptions(layer.frame.size, layer.isOpaque, scale)
defer {
UIGraphicsEndImageContext()
}
guard let ctx = UIGraphicsGetCurrentContext() else { return nil }
layer.render(in: ctx)
let image = UIGraphicsGetImageFromCurrentImageContext()
return image
}
// MARK: 1.5、设置图片透明度
/// 设置图片透明度
/// alpha: 透明度
/// - Returns: newImage
func imageByApplayingAlpha(_ alpha: CGFloat) -> UIImage {
UIGraphicsBeginImageContext(size)
let context = UIGraphicsGetCurrentContext()
let area = CGRect(x: 0, y: 0, width: size.width, height: size.height)
context?.scaleBy(x: 1, y: -1)
context?.translateBy(x: 0, y: -area.height)
context?.setBlendMode(.multiply)
context?.setAlpha(alpha)
context?.draw(self.cgImage!, in: area)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage ?? self
}
// MARK: 1.6、裁剪给定区域
/// 裁剪给定区域
/// - Parameter crop: 裁剪区域
/// - Returns: 剪裁后的图片
func cropWithCropRect( _ crop: CGRect) -> UIImage? {
let cropRect = CGRect(x: crop.origin.x * self.scale, y: crop.origin.y * self.scale, width: crop.size.width * self.scale, height: crop.size.height * self.scale)
if cropRect.size.width <= 0 || cropRect.size.height <= 0 {
return nil
}
var image:UIImage?
autoreleasepool{
let imageRef: CGImage? = self.cgImage!.cropping(to: cropRect)
if let imageRef = imageRef {
image = UIImage(cgImage: imageRef)
}
}
return image
}
// MARK: 1.7、给图片添加文字水印
/// 给图片添加文字水印
/// - Parameters:
/// - drawTextframe: 水印的 frame
/// - drawText: 水印文字
/// - withAttributes: 水印富文本
/// - Returns: 返回水印图片
func drawTextInImage(drawTextframe: CGRect, drawText: String, withAttributes: [NSAttributedString.Key : Any]? = nil) -> UIImage {
// 开启图片上下文
UIGraphicsBeginImageContext(self.size)
// 图形重绘
self.draw(in: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))
// 水印文字属性
let attributes = withAttributes
// 水印文字和大小
let text = NSString(string: drawText)
// 获取富文本的 size
// let size = text.size(withAttributes: attributes)
// 绘制文字
text.draw(in: drawTextframe, withAttributes: attributes)
// 从当前上下文获取图片
let image = UIGraphicsGetImageFromCurrentImageContext()
// 关闭上下文
UIGraphicsEndImageContext()
return image!
}
}
二、UIColor 生成的图片 和 生成渐变色图片
// MARK:- 二、UIColor 生成的图片 和 生成渐变色图片
public extension UIImage {
// MARK: 2.1、生成指定尺寸的纯色图像
/// 生成指定尺寸的纯色图像
/// - Parameters:
/// - color: 图片颜色
/// - size: 图片尺寸
/// - Returns: 返回对应的图片
static func image(color: UIColor, size: CGSize = CGSize(width: 1.0, height: 1.0)) -> UIImage? {
return image(color: color, size: size, corners: .allCorners, radius: 0)
}
// MARK: 2.2、生成指定尺寸和圆角的纯色图像
/// 生成指定尺寸和圆角的纯色图像
/// - Parameters:
/// - color: 图片颜色
/// - size: 图片尺寸
/// - corners: 剪切的方式
/// - round: 圆角大小
/// - Returns: 返回对应的图片
static func image(color: UIColor, size: CGSize, corners: UIRectCorner, radius: CGFloat) -> UIImage? {
let rect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
UIGraphicsBeginImageContextWithOptions(size, false, UIScreen.main.scale)
let context = UIGraphicsGetCurrentContext()
if radius > 0 {
let path = UIBezierPath(roundedRect: rect, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
color.setFill()
path.fill()
} else {
context?.setFillColor(color.cgColor)
context?.fill(rect)
}
let img = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return img
}
enum GradientDirection {
case horizontal // 水平从左到右
case vertical // 垂直从上到下
case leftOblique // 左上到右下
case rightOblique // 右上到左下
case other(CGPoint, CGPoint)
public func point(size: CGSize) -> (CGPoint, CGPoint) {
switch self {
case .horizontal:
return (CGPoint.init(x: 0, y: 0), CGPoint.init(x: size.width, y: 0))
case .vertical:
return (CGPoint.init(x: 0, y: 0), CGPoint.init(x: 0, y: size.height))
case .leftOblique:
return (CGPoint.init(x: 0, y: 0), CGPoint.init(x: size.width, y: size.height))
case .rightOblique:
return (CGPoint.init(x: size.width, y: 0), CGPoint.init(x: 0, y: size.height))
case .other(let stat, let end):
return (stat, end)
}
}
}
// MARK: 2.3、生成渐变色的图片 ["#B0E0E6", "#00CED1", "#2E8B57"]
/// 生成渐变色的图片 ["#B0E0E6", "#00CED1", "#2E8B57"]
/// - Parameters:
/// - hexsString: 十六进制字符数组
/// - size: 图片大小
/// - locations: locations 数组
/// - direction: 渐变的方向
/// - Returns: 渐变的图片
static func gradient(_ hexsString: [String], size: CGSize = CGSize(width: 1, height: 1), locations:[CGFloat]? = nil, direction: GradientDirection = .horizontal) -> UIImage? {
return gradient(hexsString.map{ UIColor.hexStringColor(hexString: $0) }, size: size, locations: locations, direction: direction)
}
// MARK: 2.4、生成渐变色的图片 [UIColor, UIColor, UIColor]
/// 生成渐变色的图片 [UIColor, UIColor, UIColor]
/// - Parameters:
/// - colors: UIColor 数组
/// - size: 图片大小
/// - locations: locations 数组
/// - direction: 渐变的方向
/// - Returns: 渐变的图片
static func gradient(_ colors: [UIColor], size: CGSize = CGSize(width: 10, height: 10), locations:[CGFloat]? = nil, direction: GradientDirection = .horizontal) -> UIImage? {
return gradient(colors, size: size, radius: 0, locations: locations, direction: direction)
}
// MARK: 2.5、生成带圆角渐变色的图片 [UIColor, UIColor, UIColor]
/// 生成带圆角渐变色的图片 [UIColor, UIColor, UIColor]
/// - Parameters:
/// - colors: UIColor 数组
/// - size: 图片大小
/// - radius: 圆角
/// - locations: locations 数组
/// - direction: 渐变的方向
/// - Returns: 带圆角的渐变的图片
static func gradient(_ colors: [UIColor],
size: CGSize = CGSize(width: 10, height: 10),
radius: CGFloat,
locations:[CGFloat]? = nil,
direction: GradientDirection = .horizontal) -> UIImage? {
if colors.count == 0 { return nil }
if colors.count == 1 {
return UIImage.image(color: colors[0])
}
UIGraphicsBeginImageContext(size)
let context = UIGraphicsGetCurrentContext()
let path = UIBezierPath(roundedRect: CGRect(x: 0, y: 0, width: size.width, height: size.height), cornerRadius: radius)
path.addClip()
context?.addPath(path.cgPath)
guard let gradient = CGGradient(colorsSpace: CGColorSpaceCreateDeviceRGB(), colors: colors.map{$0.cgColor} as CFArray, locations: locations?.map { CGFloat($0) }) else { return nil
}
let directionPoint = direction.point(size: size)
context?.drawLinearGradient(gradient, start: directionPoint.0, end: directionPoint.1, options: .drawsBeforeStartLocation)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
}
三、图片的拉伸和缩放
// MARK:- 三、图片的拉伸和缩放
public extension UIImage {
// MARK: 3.1、获取固定大小的 image
/// 获取固定大小的image
/// - Parameter size: 图片尺寸
/// - Returns: 固定大小的 image
func solidTo(size: CGSize) -> UIImage? {
let w = size.width
let h = size.height
if self.size.height <= self.size.width {
if self.size.width >= w {
let scaleImage = fixOrientation().scaleTo(size: CGSize(width: w, height: w * self.size.height / self.size.width))
return scaleImage
} else {
return fixOrientation()
}
} else {
if self.size.height >= h {
let scaleImage = fixOrientation().scaleTo(size: CGSize(width: h * self.size.width / self.size.height, height: h))
return scaleImage
} else {
return fixOrientation()
}
}
}
// MARK: 3.2、按宽高比系数：等比缩放
/// 按宽高比系数：等比缩放
/// - Parameter scale: 要缩放的 宽高比 系数
/// - Returns: 等比缩放 后的图片
func scaleTo(scale: CGFloat) -> UIImage? {
let w = self.size.width
let h = self.size.height
let scaledW = w * scale
let scaledH = h * scale
UIGraphicsBeginImageContext(size)
self.draw(in: CGRect(x: 0, y: 0, width: scaledW, height: scaledH))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage;
}
// MARK: 3.3、按指定尺寸等比缩放
/// 按指定尺寸等比缩放
/// - Parameter size: 要缩放的尺寸
/// - Returns: 缩放后的图片
func scaleTo(size: CGSize) -> UIImage? {
if self.cgImage == nil { return nil }
var w = CGFloat(self.cgImage!.width)
var h = CGFloat(self.cgImage!.height)
let verticalRadio = size.height / h
let horizontalRadio = size.width / w
var radio: CGFloat = 1
if verticalRadio > 1 && horizontalRadio > 1 {
radio = verticalRadio > horizontalRadio ? horizontalRadio : verticalRadio
} else {
radio = verticalRadio < horizontalRadio ? verticalRadio : horizontalRadio
}
w = w * radio;
h = h * radio;
let xPos = (size.width - w) / 2;
let yPos = (size.height - h) / 2;
UIGraphicsBeginImageContext(size);
draw(in: CGRect(x: xPos, y: yPos, width: w, height: h))
let scaledImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return scaledImage;
}
// MARK: 3.4、图片中间 1*1 拉伸——如气泡一般
/// 图片中间1*1拉伸——如气泡一般
/// - Returns: 拉伸后的图片
func strechAsBubble() -> UIImage {
let top = self.size.height * 0.5;
let left = self.size.width * 0.5;
let bottom = self.size.height * 0.5;
let right = self.size.width * 0.5;
let edgeInsets = UIEdgeInsets(top: top, left: left, bottom: bottom, right: right);
// 拉伸
return self.resizableImage(withCapInsets: edgeInsets, resizingMode: .stretch)
}
// MARK: 3.5、调整图像方向 避免图像有旋转
/// 调整图像方向 避免图像有旋转
/// - Returns: 返正常的图片
func fixOrientation() -> UIImage {
if imageOrientation == .up {
return self
}
var transform: CGAffineTransform = CGAffineTransform.identity
switch imageOrientation {
case .down, .downMirrored:
transform = transform.translatedBy(x: size.width, y: size.height)
transform = transform.rotated(by: .pi)
case .left, .leftMirrored:
transform = transform.translatedBy(x: size.width, y: 0)
transform = transform.rotated(by: .pi / 2)
case .right, .rightMirrored:
transform = transform.translatedBy(x: 0, y: size.height)
transform = transform.rotated(by: -.pi / 2)
default:
break
}
switch imageOrientation {
case .upMirrored, .downMirrored:
transform.translatedBy(x: size.width, y: 0)
transform.scaledBy(x: -1, y: 1)
case .leftMirrored, .rightMirrored:
transform.translatedBy(x: size.height, y: 0)
transform.scaledBy(x: -1, y: 1)
default:
break
}
let ctx: CGContext = CGContext(data: nil, width: Int(size.width), height: Int(size.height), bitsPerComponent: (self.cgImage?.bitsPerComponent)!, bytesPerRow: 0, space: (self.cgImage?.colorSpace)!, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)!
ctx.concatenate(transform)
switch imageOrientation {
case .left, .leftMirrored, .right, .rightMirrored:
ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: size.height, height: size.width))
default:
ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
}
let cgImage: CGImage = ctx.makeImage()!
return UIImage(cgImage: cgImage)
}
}
四、UIImage 压缩相关
// MARK:- 四、UIImage 压缩相关
public extension UIImage {
// MARK: 4.1、压缩图片
/// 压缩图片
/// - Parameter mode: 压缩模式
/// - Returns: 压缩后Data
func compress(mode: CompressionMode = .medium) -> Data? {
return resizeIO(resizeSize: mode.resize(size))?.compressDataSize(maxSize: mode.maxDataSize)
}
// MARK: 4.2、异步图片压缩
/// 异步图片压缩
/// - Parameters:
/// - mode: 压缩模式
/// - queue: 压缩队列
/// - complete: 完成回调(压缩后Data, 调整后分辨率)
func asyncCompress(mode: CompressionMode = .medium, queue: DispatchQueue = DispatchQueue.global(), complete:@escaping (Data?, CGSize) -> Void) {
queue.async {
let data = self.resizeIO(resizeSize: mode.resize(self.size))?.compressDataSize(maxSize: mode.maxDataSize)
DispatchQueue.main.async {
complete(data, mode.resize(self.size))
}
}
}
// MARK: 4.3、压缩图片质量
/// 压缩图片质量
/// - Parameter maxSize: 最大数据大小
/// - Returns: 压缩后数据
func compressDataSize(maxSize: Int = 1024 * 1024 * 2) -> Data? {
let maxSize = maxSize
var quality: CGFloat = 0.8
var data = self.jpegData(compressionQuality: quality)
var dataCount = data?.count ?? 0
while (data?.count ?? 0) > maxSize {
if quality <= 0.6 {
break
}
quality = quality - 0.05
data = self.jpegData(compressionQuality: quality)
if (data?.count ?? 0) <= dataCount {
break
}
dataCount = data?.count ?? 0
}
return data
}
// MARK: 4.4、ImageIO 方式调整图片大小 性能很好
/// ImageIO 方式调整图片大小 性能很好
/// - Parameter resizeSize: 图片调整Size
/// - Returns: 调整后图片
func resizeIO(resizeSize: CGSize) -> UIImage? {
if size == resizeSize {
return self
}
guard let imageData = pngData() else { return nil }
guard let imageSource = CGImageSourceCreateWithData(imageData as CFData, nil) else { return nil }
let maxPixelSize = max(size.width, size.height)
let options = [kCGImageSourceCreateThumbnailWithTransform: true,
kCGImageSourceCreateThumbnailFromImageIfAbsent: true,
kCGImageSourceThumbnailMaxPixelSize: maxPixelSize] as CFDictionary
let resizedImage = CGImageSourceCreateThumbnailAtIndex(imageSource, 0, options).flatMap{
UIImage(cgImage: $0)
}
return resizedImage
}
// MARK: 4.5、CoreGraphics 方式调整图片大小 性能很好
/// CoreGraphics 方式调整图片大小 性能很好
/// - Parameter resizeSize: 图片调整Size
/// - Returns: 调整后图片
func resizeCG(resizeSize: CGSize) -> UIImage? {
if size == resizeSize {
return self
}
guard let cgImage = self.cgImage else { return nil }
guard let colorSpace = cgImage.colorSpace else { return nil }
guard let context = CGContext(data: nil,
width: Int(resizeSize.width),
height: Int(resizeSize.height),
bitsPerComponent: cgImage.bitsPerComponent,
bytesPerRow: cgImage.bytesPerRow,
space: colorSpace,
bitmapInfo: cgImage.bitmapInfo.rawValue) else { return nil }
context.interpolationQuality = .high
context.draw(cgImage, in: CGRect(origin: .zero, size: resizeSize))
let resizedImage = context.makeImage().flatMap {
UIImage(cgImage: $0)
}
return resizedImage
}
}
// MARK: 压缩模式
public enum CompressionMode {
/// 分辨率规则
private static let resolutionRule: (min: CGFloat, max: CGFloat, low: CGFloat, default: CGFloat, high: CGFloat) = (10, 4096, 512, 1024, 2048)
/// 数据大小规则
private static let dataSizeRule: (min: Int, max: Int, low: Int, default: Int, high: Int) = (1024 * 10, 1024 * 1024 * 20, 1024 * 512, 1024 * 1024 * 2, 1024 * 1024 * 10)
// 低质量
case low
// 中等质量 默认
case medium
// 高质量
case high
// 自定义(最大分辨率, 最大输出数据大小)
case other(CGFloat, Int)
fileprivate var maxDataSize: Int {
switch self {
case .low:
return CompressionMode.dataSizeRule.low
case .medium:
return CompressionMode.dataSizeRule.default
case .high:
return CompressionMode.dataSizeRule.high
case .other(_, let dataSize):
if dataSize < CompressionMode.dataSizeRule.min {
return CompressionMode.dataSizeRule.default
}
if dataSize > CompressionMode.dataSizeRule.max {
return CompressionMode.dataSizeRule.max
}
return dataSize
}
}
fileprivate func resize(_ size: CGSize) -> CGSize {
if size.width < CompressionMode.resolutionRule.min || size.height < CompressionMode.resolutionRule.min {
return size
}
let maxResolution = maxSize
let aspectRatio = max(size.width, size.height) / maxResolution
if aspectRatio <= 1.0 {
return size
} else {
let resizeWidth = size.width / aspectRatio
let resizeHeighth = size.height / aspectRatio
if resizeHeighth < CompressionMode.resolutionRule.min || resizeWidth < CompressionMode.resolutionRule.min {
return size
} else {
return CGSize.init(width: resizeWidth, height: resizeHeighth)
}
}
}
fileprivate var maxSize: CGFloat {
switch self {
case .low:
return CompressionMode.resolutionRule.low
case .medium:
return CompressionMode.resolutionRule.default
case .high:
return CompressionMode.resolutionRule.high
case .other(let size, _):
if size < CompressionMode.resolutionRule.min {
return CompressionMode.resolutionRule.default
}
if size > CompressionMode.resolutionRule.max {
return CompressionMode.resolutionRule.max
}
return size
}
}
}
五、二维码的处理
// MARK:- 五、二维码的处理
public extension UIImage {
// MARK: 5.1、生成二维码图片
/// 生成二维码图片
/// - Parameters:
/// - content: 二维码里面的内容
/// - size: 二维码的大小
/// - logoSize: logo的大小
/// - logoImage: logo图片
/// - Returns: 返回生成二维码图片
static func QRImage(with content: String, size: CGSize, isLogo: Bool = true, logoSize: CGSize?, logoImage: UIImage? = nil, logoRoundCorner: CGFloat? = nil) -> UIImage? {
// 1、创建名为"CIQRCodeGenerator"的CIFilter
let filter = CIFilter(name: "CIQRCodeGenerator")
// 2、将filter所有属性设置为默认值
filter?.setDefaults()
// 3、将所需尽心转为UTF8的数据，并设置给filter
let data = content.data(using: String.Encoding.utf8)
filter?.setValue(data, forKey: "inputMessage")
// 4、设置二维码的纠错水平，越高纠错水平越高，可以污损的范围越大
/*
L: 7%
M: 15%
Q: 25%
H: 30%
*/
filter?.setValue("H", forKey: "inputCorrectionLevel")
// 5、拿到二维码图片，此时的图片不是很清晰，需要二次加工
guard let outPutImage = filter?.outputImage else { return nil }
return getHDImgWithCIImage(with: outPutImage, size: size, isLogo: isLogo, logoSize: logoSize, logoImage: logoImage, logoRoundCorner: logoRoundCorner)
}
// MARK: 调整二维码清晰度，添加水印图片
/// 调整二维码清晰度，添加水印图片
/// - Parameters:
/// - image: 模糊的二维码图片
/// - size: 二维码的宽高
/// - logoSize: logo的大小
/// - logoImage: logo图片
/// - Returns: 添加 logo 图片后，清晰的二维码图片
private static func getHDImgWithCIImage(with image: CIImage, size: CGSize, isLogo: Bool = true, logoSize: CGSize?, logoImage: UIImage? = nil, logoRoundCorner: CGFloat? = nil) -> UIImage? {
let extent = image.extent.integral
let scale = min(size.width / extent.width, size.height / extent.height)
//1.创建bitmap
let width = extent.width * scale
let height = extent.height * scale
// 创建基于GPU的CIContext对象,性能和效果更好
let context = CIContext(options: nil)
// 创建CoreGraphics image
guard let bitmapImage = context.createCGImage(image, from: extent) else { return nil }
// 创建一个DeviceGray颜色空间
let cs = CGColorSpaceCreateDeviceGray()
// CGBitmapContextCreate(void * _Nullable data, size_t width, size_t height, size_t bitsPerComponent, size_t bytesPerRow, CGColorSpaceRef _Nullable space, uint32_t bitmapInfo)
// width：图片宽度像素
// height：图片高度像素
// bitsPerComponent：每个颜色的比特值，例如在rgba-32模式下为8
// bitmapInfo：指定的位图应该包含一个alpha通道
let bitmapRef = CGContext(data: nil, width: Int(width), height: Int(height), bitsPerComponent: 8, bytesPerRow: 0, space: cs, bitmapInfo: CGImageAlphaInfo.none.rawValue) //图形上下文，画布
bitmapRef?.interpolationQuality = CGInterpolationQuality.none //写入质量
bitmapRef?.scaleBy(x: scale, y: scale) //调整“画布”的缩放
bitmapRef?.draw(bitmapImage, in: extent) //绘制图片
//2.保存bitmap到图片
guard let scaledImage = bitmapRef?.makeImage() else { return nil }
// 清晰的二维码图片
let outputImage = UIImage(cgImage: scaledImage)
guard isLogo == true, let logoSize = logoSize, let logoImage = logoImage else {
return outputImage
}
var newLogo: UIImage = logoImage
if let newLogoRoundCorner = logoRoundCorner, let roundCornerLogo = logoImage.isRoundCorner(radius: newLogoRoundCorner, byRoundingCorners: .allCorners, imageSize: logoSize) {
newLogo = roundCornerLogo
}
// 给二维码加 logo 图
UIGraphicsBeginImageContextWithOptions(outputImage.size, false, UIScreen.main.scale)
outputImage.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
// 把水印图片画到生成的二维码图片上，注意尺寸不要太大（根据上面生成二维码设置的纠错程度设置），否则有可能造成扫不出来
let waterImgW = logoSize.width
let waterImgH = logoSize.height
let waterImgX = (size.width - waterImgW) * 0.5
let waterImgY = (size.height - waterImgH) * 0.5
newLogo.draw(in: CGRect(x: waterImgX, y: waterImgY, width: waterImgW, height: waterImgH))
let newPicture = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newPicture
}
}
六、gif 加载
// MARK:- 六、pdf 加载
public enum DataType: String {
case gif = "gif"
case png = "png"
case jpeg = "jpeg"
case tiff = "tiff"
case defaultType
}
public extension UIImage {
// MARK: 6.1、验证资源的格式，返回资源格式（png/gif/jpeg...）
/// 验证资源的格式，返回资源格式（png/gif/jpeg...）
/// - Parameter data: 资源
/// - Returns: 返回资源格式（png/gif/jpeg...）
static func checkImageDataType(data: Data?) -> DataType {
guard data != nil else {
return .defaultType
}
let c = data![0]
switch (c) {
case 0xFF:
return .jpeg
case 0x89:
return .png
case 0x47:
return .gif
case 0x49, 0x4D:
return .tiff
default:
return .defaultType
}
}
// MARK: 6.2、加载 data 数据的 gif 图片
/// 加载 data 数据的 gif 图片
/// - Parameter data: data 数据
static func gif(data: Data) -> UIImage? {
// Create source from data
guard let source = CGImageSourceCreateWithData(data as CFData, nil) else {
print("SwiftGif: Source for the image does not exist")
return nil
}
return UIImage.animatedImageWithSource(source)
}
// MARK: 6.3、加载网络 url 的 gif 图片
/// 加载网络 url 的 gif 图片
/// - Parameter url: gif图片的网络地址
static func gif(url: String) -> UIImage? {
// Validate URL
guard let bundleURL = URL(string: url) else {
print("SwiftGif: This image named \"\(url)\" does not exist")
return nil
}
// Validate data
guard let imageData = try? Data(contentsOf: bundleURL) else {
print("SwiftGif: Cannot turn image named \"\(url)\" into NSData")
return nil
}
return gif(data: imageData)
}
// MARK: 6.4、加载本地的gif图片
/// 加载本地的gif图片
/// - Parameter name:图片的名字
static func gif(name: String) -> UIImage? {
// Check for existance of gif
guard let bundleURL = Bundle.main
.url(forResource: name, withExtension: "gif") else {
print("SwiftGif: This image named \"\(name)\" does not exist")
return nil
}
// Validate data
guard let imageData = try? Data(contentsOf: bundleURL) else {
print("SwiftGif: Cannot turn image named \"\(name)\" into NSData")
return nil
}
return gif(data: imageData)
}
// MARK: 6.5、加载 asset 里面的图片
/// 加载 asset 里面的图片
/// - Parameter asset: asset 里面的图片名字
@available(iOS 9.0, *)
static func gif(asset: String) -> UIImage? {
// Create source from assets catalog
guard let dataAsset = NSDataAsset(name: asset) else {
print("SwiftGif: Cannot turn image named \"\(asset)\" into NSDataAsset")
return nil
}
return gif(data: dataAsset.data)
}
private class func delayForImageAtIndex(_ index: Int, source: CGImageSource!) -> Double {
var delay = 0.1
// Get dictionaries
let cfProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil)
let gifPropertiesPointer = UnsafeMutablePointer<UnsafeRawPointer?>.allocate(capacity: 0)
defer {
gifPropertiesPointer.deallocate()
}
let unsafePointer = Unmanaged.passUnretained(kCGImagePropertyGIFDictionary).toOpaque()
if CFDictionaryGetValueIfPresent(cfProperties, unsafePointer, gifPropertiesPointer) == false {
return delay
}
let gifProperties: CFDictionary = unsafeBitCast(gifPropertiesPointer.pointee, to: CFDictionary.self)
// Get delay time
var delayObject: AnyObject = unsafeBitCast(
CFDictionaryGetValue(gifProperties,
Unmanaged.passUnretained(kCGImagePropertyGIFUnclampedDelayTime).toOpaque()),
to: AnyObject.self)
if delayObject.doubleValue == 0 {
delayObject = unsafeBitCast(CFDictionaryGetValue(gifProperties,
Unmanaged.passUnretained(kCGImagePropertyGIFDelayTime).toOpaque()), to: AnyObject.self)
}
if let delayObject = delayObject as? Double, delayObject > 0 {
delay = delayObject
} else {
// Make sure they're not too fast
delay = 0.1
}
return delay
}
private static func gcdForPair(_ lhs: Int?, _ rhs: Int?) -> Int {
var lhs = lhs
var rhs = rhs
// Check if one of them is nil
if rhs == nil || lhs == nil {
if rhs != nil {
return rhs!
} else if lhs != nil {
return lhs!
} else {
return 0
}
}
// Swap for modulo
if lhs! < rhs! {
let ctp = lhs
lhs = rhs
rhs = ctp
}
// Get greatest common divisor
var rest: Int
while true {
rest = lhs! % rhs!
if rest == 0 {
return rhs!
} else {
lhs = rhs
rhs = rest
}
}
}
private static func gcdForArray(_ array: [Int]) -> Int {
if array.isEmpty {
return 1
}
var gcd = array[0]
for val in array {
gcd = UIImage.gcdForPair(val, gcd)
}
return gcd
}
private static func animatedImageWithSource(_ source: CGImageSource) -> UIImage? {
let count = CGImageSourceGetCount(source)
var images = [CGImage]()
var delays = [Int]()
// Fill arrays
for index in 0..<count {
// Add image
if let image = CGImageSourceCreateImageAtIndex(source, index, nil) {
images.append(image)
}
// At it's delay in cs
let delaySeconds = UIImage.delayForImageAtIndex(Int(index),
source: source)
delays.append(Int(delaySeconds * 1000.0)) // Seconds to ms
}
// Calculate full duration
let duration: Int = {
var sum = 0
for val: Int in delays {
sum += val
}
return sum
}()
// Get frames
let gcd = gcdForArray(delays)
var frames = [UIImage]()
var frame: UIImage
var frameCount: Int
for index in 0..<count {
frame = UIImage(cgImage: images[Int(index)])
frameCount = Int(delays[Int(index)] / gcd)
for _ in 0..<frameCount {
frames.append(frame)
}
}
// Heyhey
let animation = UIImage.animatedImage(with: frames,
duration: Double(duration) / 1000.0)
return animation
}
}
