swift---自用圆形头像控件(继承UIControl)

此控件搭配Kingfisher使用，你也可以自己替换成SD。继承UIControl，可以不用再去加手势，直接调用UIControl 的addTarget...方法实现点击事件

直接上代码

class ImageView: UIControl {
    
    
    /// 图像类型
    ///
    /// - none: 矩形直角
    /// - round: 圆形
    /// - radius: 圆角
    enum AvatarType {
        case none, round, radius(CGFloat)
    }
    
    var image: UIImage? {
        didSet {
            if image != oldValue {
                setNeedsDisplay()
            }
        }
    }
    
    var defaultImage: UIImage? {
        didSet {
            if defaultImage != oldValue {
                setNeedsDisplay()
            }
        }
    }
    
    var highlightedImage: UIImage? {
        didSet {
            if highlightedImage != oldValue {
                setNeedsDisplay()
            }
        }
    }
    
    override var isHighlighted: Bool {
        didSet {
            setNeedsDisplay()
        }
    }
    
    override var isSelected: Bool {
        didSet {
            setNeedsDisplay()
        }
    }

    
    init(frame: CGRect, type: AvatarType = .round) {
        self.type = type
        super.init(frame: frame)
        setup()
    }
    
    required init?(coder aDecoder: NSCoder) {
        self.type = .none
        super.init(coder: aDecoder)
        setup()
    }
    
    private let type: AvatarType
    private var cornerRadius: CGFloat = 0
    
    override func draw(_ rect: CGRect) {
        guard bounds.width > 0, bounds.height > 0 else {
            return
        }
        
        let context = UIGraphicsGetCurrentContext()
        let img = UIImageView()
        context?.saveGState()
        defer {
            context?.restoreGState()
        }
        
        if cornerRadius > 0 {
            // 防止中途改变size
            if case .round = type {
                cornerRadius = bounds.size.width * 0.5
            }
            context?.addPath(UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).cgPath)
            context?.clip()
        }
        
        if let image = showImage(), image.size.height > 0, image.size.width > 0, let cgImage = image.cgImage {
            //ScaleAspectFill模式
            let newCenter = CGPoint(x: bounds.width * 0.5, y: bounds.height * 0.5)
            //哪个小按哪个缩
            let scaleW = image.size.width / bounds.width
            let scaleH = image.size.height / bounds.height
            let scale = min(scaleW, scaleH)
            
            let newSize = CGSize(width: image.size.width / scale, height: image.size.height / scale)
            
            let drawRect = CGRect(x: newCenter.x - newSize.width / 2, y: newCenter.y - newSize.height / 2, width: newSize.width, height: newSize.height)
            context?.draw(cgImage, in: drawRect)
        }
    }

}

extension ImageView {
    fileprivate func setup() {
        backgroundColor = UIColor.clear
        layer.isGeometryFlipped = true
        switch type {
        case .none: cornerRadius = 0.0
        case .round: cornerRadius = bounds.size.width * 0.5
        case .radius(let radius): cornerRadius = radius
        }
    }
    
    fileprivate func showImage() -> UIImage? {
        let current = (state == .highlighted || state == .selected)
        let img = image ?? defaultImage
        return current ? (highlightedImage != nil) ? highlightedImage : img : img
    }
}

下面是控件调用url，网络请求赋值的方法

extension ImageView {
    
    func image(for url: String?) {
        guard let url = url else { return }
        let Url = URL(string: url)
        image(for: Url)
    }
    
    @discardableResult
    func image(for resource: Resource?,
               placeholder: UIImage? = nil,
               options: KingfisherOptionsInfo? = nil,
               progressBlock: DownloadProgressBlock? = nil,
               completionHandler: CompletionHandler? = nil) -> RetrieveImageTask {
        guard let resource = resource else {
            image = placeholder
            setWebURL(nil)
            completionHandler?(nil, nil, .none, nil)
            return .empty
        }
        
        var options = KingfisherManager.shared.defaultOptions + (options ?? [])
        
        if !options.keepCurrentImageWhileLoading {
            image = placeholder
        }
        
        setWebURL(resource.downloadURL)
        
        if shouldPreloadAllAnimation()  {
            options.append(.preloadAllAnimationData)
        }
        
        let task = KingfisherManager.shared.retrieveImage(with: resource, options: options, progressBlock: { receivedSize, totalSize in
            guard resource.downloadURL == self.webURL else { return }
            if let progressBlock = progressBlock {
                progressBlock(receivedSize, totalSize)
            }
        }) { [weak self] image, error, cacheType, imageURL in
            DispatchQueue.main.safeAsync {
                guard let strongSelf = self, imageURL == strongSelf.webURL else {
                    completionHandler?(image, error, cacheType, imageURL)
                    return
                }
                
                self?.setImageTask(nil)
                guard let img = image else {
                    completionHandler?(nil, error, cacheType, imageURL)
                    return
                }
                
                strongSelf.image = img
                completionHandler?(img, error, cacheType, imageURL)
                
            }
        }
        
        setImageTask(task)
        
        return task
    }
}

取消网络请求的方法

func cancelDownloadTask() {
        imageTask?.cancel()
    }

使用runtime在网络请求的时候为控件的属性赋值

private var lastURLKey: Void?
private var imageTaskKey: Void?
extension ImageView {
    var webURL: URL? {
        return objc_getAssociatedObject(self, &lastURLKey) as? URL
    }
    fileprivate func setWebURL(_ url: URL?) {
        objc_setAssociatedObject(self, &lastURLKey, url, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
    }
    
    fileprivate var imageTask: RetrieveImageTask? {
        return objc_getAssociatedObject(self, &imageTaskKey) as? RetrieveImageTask
    }
    
    fileprivate func setImageTask(_ task: RetrieveImageTask?) {
        objc_setAssociatedObject(self, &imageTaskKey, task, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
    }
    fileprivate func shouldPreloadAllAnimation() -> Bool { return true }
}