根据color和size生成新的图片
extension UIImage {
public class func image(color: UIColor, size: CGSize) -> UIImage? {
if size.width <= 0 || size.height <= 0 {
return nil
}
let rect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
UIGraphicsBeginImageContextWithOptions(size, false, 0)
let context = UIGraphicsGetCurrentContext()
context?.setFillColor(color.cgColor)
context?.fill(rect)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
}
根据radius,corners,borderWidth,borderColor,borderLineJoin生成新的图片
extension UIImage {
public func image(radius: CGFloat, borderWidth: CGFloat, borderColor: UIColor) -> UIImage? {
return image(radius: radius, corners: UIRectCorner.allCorners, borderWidth: borderWidth, borderColor: borderColor, borderLineJoin: .miter)
}
public func image(radius: CGFloat, corners: UIRectCorner, borderWidth: CGFloat, borderColor: UIColor, borderLineJoin: CGLineJoin) -> UIImage? {
/*
/* Line join styles. */
public enum CGLineJoin : Int32 {
case miter
case round
case bevel
}
*/
UIGraphicsBeginImageContextWithOptions(size, false, scale)
let context = UIGraphicsGetCurrentContext()
let rect = CGRect(x: 0, y: 0, width: size.width, height: size.height)
context?.scaleBy(x: 1, y: -1)
context?.translateBy(x: 0, y: -rect.size.height)
let minSize = min(size.width, size.height)
if borderWidth < minSize / 2 {
let path = UIBezierPath.init(roundedRect: rect.insetBy(dx: borderWidth, dy: borderWidth), byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: borderWidth))
path.close()
context?.saveGState()
path.addClip()
context?.draw(cgImage!, in: rect)
context?.restoreGState()
}
if borderWidth > 0 && borderWidth < minSize / 2 {
let strokeInset = (floor(borderWidth*scale)+0.5) / scale
let strokeRect = rect.insetBy(dx: strokeInset, dy: strokeInset)
let strokeRadius = radius > scale / 2 ? radius-scale/2 : 0
let path = UIBezierPath.init(roundedRect: strokeRect, byRoundingCorners: corners, cornerRadii: CGSize(width: strokeRadius, height: borderWidth))
path.close()
path.lineWidth = borderWidth
path.lineJoinStyle = borderLineJoin
borderColor.setStroke()
path.stroke()
}
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
}
图片压缩
extension UIImage {
public func compressed(quality: CGFloat = 0.5) -> UIImage? {
guard let data = compressedData(quality: quality) else { return nil }
return UIImage(data: data)
}
public func compressedData(quality: CGFloat = 0.5) -> Data? {
return UIImageJPEGRepresentation(self, quality)
}
}
图片缩放
extension UIImage {
public func scaled(toHeight: CGFloat, opaque: Bool = false, with orientation: UIImageOrientation? = nil) -> UIImage? {
let scale = toHeight / size.height
let newWidth = size.width * scale
UIGraphicsBeginImageContextWithOptions(CGSize(width: newWidth, height: toHeight), opaque, scale)
draw(in: CGRect(x: 0, y: 0, width: newWidth, height: toHeight))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
public func scaled(toWidth: CGFloat, opaque: Bool = false, with orientation: UIImageOrientation? = nil) -> UIImage? {
let scale = toWidth / size.width
let newHeight = size.height * scale
UIGraphicsBeginImageContextWithOptions(CGSize(width: toWidth, height: newHeight), opaque, scale)
draw(in: CGRect(x: 0, y: 0, width: toWidth, height: newHeight))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
}
圆角图片
extension UIImage {
public func withRoundedCorners(radius: CGFloat? = nil) -> UIImage? {
let maxRadius = min(size.width, size.height) / 2
let cornerRadius: CGFloat
if let radius = radius, radius > 0 && radius <= maxRadius {
cornerRadius = radius
} else {
cornerRadius = maxRadius
}
UIGraphicsBeginImageContextWithOptions(size, false, scale)
let rect = CGRect(origin: .zero, size: size)
UIBezierPath(roundedRect: rect, cornerRadius: cornerRadius).addClip()
draw(in: rect)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
}
初始化方法
extension UIImage {
//init with color and size
public convenience init(color: UIColor, size: CGSize) {
UIGraphicsBeginImageContextWithOptions(size, false, 1)
color.setFill()
UIRectFill(CGRect(x: 0, y: 0, width: size.width, height: size.height))
guard let image = UIGraphicsGetImageFromCurrentImageContext() else {
self.init()
return
}
UIGraphicsEndImageContext()
guard let aCgImage = image.cgImage else {
self.init()
return
}
self.init(cgImage: aCgImage)
}
// simplified contentsOfFile: method
public convenience init(fileNamed: String) {
let path = UIImage.createLocalUrl(forImageNamed: fileNamed)?.path
self.init(contentsOfFile: path!)!
}
static func createLocalUrl(forImageNamed name: String) -> URL? {
let fileManager = FileManager.default
let cacheDirectory = fileManager.urls(for: .cachesDirectory, in: .userDomainMask)[0]
if name.contains(".jpg") {
return cacheDirectory.appendingPathComponent(name)
}
let scale = UIScreen.main.scale
var scaleName = ""
switch scale {
case 2:
scaleName = name + "@2x.png"
case 3:
scaleName = name + "@3x.png"
default:
scaleName = name + ".png"
}
let url = cacheDirectory.appendingPathComponent("\(scaleName)")
guard fileManager.fileExists(atPath: url.path) else {
guard
let image = UIImage(named: name),
let data = UIImagePNGRepresentation(image)
else { return nil }
fileManager.createFile(atPath: url.path, contents: data, attributes: nil)
return url
}
return url
}
}
资源来自网络和日常整理,持续更新
网友评论