本示例包含
- 调用系统相机
- 读取系统相册图片
- 图片压缩
- 提取图片中某一点的颜色
- 把图片保存到系统相册
注意：
- 第一次运行会奔溃，根据日志中的提示在info.Plist文件中添加对应Key获取相关权限。
- 如果不压缩图片，选用相册中的高分辨率图片进行取色，在手指拖动时会有明显的卡顿
import UIKit
import Photos
class ViewController: UIViewController {
let tagView = UIView()
@IBOutlet weak var imageView: UIImageView!
@IBAction func compressionClick(_ sender: Any) {
if let image = imageView.image?.compression(size: CGSize(width: imageView.bounds.height, height: imageView.bounds.height)) {
imageView.image = image
}
}
@IBAction func saveImageClick(_ sender: Any) {
if let image = imageView.image {
UIImageWriteToSavedPhotosAlbum(image, self, #selector(saveImage(image:didFinishSavingWithError:contextInfo:)), nil)
}
}
@objc func saveImage(image: UIImage, didFinishSavingWithError error: NSError?, contextInfo: AnyObject) {
if error != nil{
print("保存失败")
}else{
print("保存成功")
}
}
//打开相机拍照
@IBAction func tackPhotoClick(_ sender: Any) {
if UIImagePickerController.isSourceTypeAvailable(.camera){
let cameraPicker = UIImagePickerController()
cameraPicker.delegate = self
cameraPicker.allowsEditing = true
cameraPicker.sourceType = .camera
//在需要的地方present出来
self.present(cameraPicker, animated: true, completion: nil)
} else {
print("不支持拍照")
}
}
//从相册选取照片
@IBAction func selectPhotoClick(_ sender: Any) {
let photoPicker = UIImagePickerController()
photoPicker.delegate = self
photoPicker.allowsEditing = true
photoPicker.sourceType = .photoLibrary
//在需要的地方present出来
self.present(photoPicker, animated: true, completion: nil)
}
override func viewDidLayoutSubviews() {
tagView.frame = CGRect(x: imageView.center.x - 10, y: imageView.center.y - 10, width: 20, height: 20)
tagView.backgroundColor = UIColor.clear
tagView.layer.borderWidth = 2
tagView.layer.borderColor = UIColor.red.cgColor
self.view.addSubview(tagView)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
let point = touch.location(in: imageView)
self.view.backgroundColor = imageView.pickColor(at: point)
self.tagView.frame = CGRect(x: point.x - 10, y: point.y - 10, width: 20, height: 20)
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
let point = touch.location(in: imageView)
self.view.backgroundColor = imageView.pickColor(at: point)
self.tagView.frame = CGRect(x: point.x - 10, y: point.y - 10, width: 20, height: 20)
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
}
}
extension ViewController:UIImagePickerControllerDelegate, UINavigationControllerDelegate {
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
//用户取消了拍照或者选择照片
print("用户取消了拍照")
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
print("获得照片============= \(info)")
if let image : UIImage = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
//显示设置的照片
self.imageView.image = image
}
self.dismiss(animated: true, completion: nil)
}
}
extension UIImage {
// 根据尺寸重新生成图片
public func compression(size: CGSize) -> UIImage? {
if self.size.height > size.height {
let width = size.height / self.size.height * self.size.width
let newImgSize = CGSize(width: width, height: size.height)
UIGraphicsBeginImageContext(newImgSize)
self.draw(in: CGRect(x: 0, y: 0, width: newImgSize.width, height: newImgSize.height))
let theImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
guard let newImg = theImage else { return nil}
return newImg
} else {
let newImgSize = CGSize(width: size.width, height: size.height)
UIGraphicsBeginImageContext(newImgSize)
self.draw(in: CGRect(x: 0, y: 0, width: newImgSize.width, height: newImgSize.height))
let theImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
guard let newImg = theImage else { return nil}
return newImg
}
}
}
extension UIView {
// 获取特定位置的颜色
public func pickColor(at position: CGPoint) -> UIColor? {
// 用来存放目标像素值
var pixel = [UInt8](repeatElement(0, count: 4))
// 颜色空间为 RGB，这决定了输出颜色的编码是 RGB 还是其他（比如 YUV）
let colorSpace = CGColorSpaceCreateDeviceRGB()
// 设置位图颜色分布为 RGBA
let bitmapInfo = CGImageAlphaInfo.premultipliedLast.rawValue
guard let context = CGContext(data: &pixel, width: 1, height: 1, bitsPerComponent: 8, bytesPerRow: 4, space: colorSpace, bitmapInfo: bitmapInfo) else {
return nil
}
// 设置 context 原点偏移为目标位置所有坐标
context.translateBy(x: -position.x, y: -position.y)
// 将图像渲染到 context 中
layer.render(in: context)
return UIColor(red: CGFloat(pixel[0]) / 255.0,
green: CGFloat(pixel[1]) / 255.0,
blue: CGFloat(pixel[2]) / 255.0,
alpha: CGFloat(pixel[3]) / 255.0)
}
public func getPointRGB(at position: CGPoint) -> (Int32,Int32,Int32)? {
// 用来存放目标像素值
var pixel = [UInt8](repeatElement(0, count: 4))
// 颜色空间为 RGB，这决定了输出颜色的编码是 RGB 还是其他（比如 YUV）
let colorSpace = CGColorSpaceCreateDeviceRGB()
// 设置位图颜色分布为 RGBA
let bitmapInfo = CGImageAlphaInfo.premultipliedLast.rawValue
guard let context = CGContext(data: &pixel, width: 1, height: 1, bitsPerComponent: 8, bytesPerRow: 4, space: colorSpace, bitmapInfo: bitmapInfo) else {
return nil
}
// 设置 context 原点偏移为目标位置所有坐标
context.translateBy(x: -position.x, y: -position.y)
// 将图像渲染到 context 中
layer.render(in: context)
let R:Int32 = Int32(pixel[0])
let G:Int32 = Int32(pixel[1])
let B:Int32 = Int32(pixel[2])
return (R,G,B)
}
}