我前面写了篇文章讲解如何给图片添加文字水印，而如果想要添加图片类型的水印也很简单，只要把原来代码里添加文字的部分改成图片即可。
3，使用样例
1，效果图如下：
（在图片左上角添加了一个半透明的logo图片）
2，为方便使用，我们通过扩展UIImage类来实现添加图片水印功能
（水印图片透明度，位置，边距都可以设置）
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//--- UIImageExtension.swift ---extension UIImage{ //水印位置枚举 enum WaterMarkCorner{ case TopLeft case TopRight case BottomLeft case BottomRight } //添加图片水印方法 func waterMarkedImage(waterMarkImage:UIImage, corner:WaterMarkCorner = .BottomRight, margin:CGPoint = CGPoint(x: 20, y: 20), alpha:CGFloat = 1) -> UIImage{ var markFrame = CGRectMake(0, 0, waterMarkImage.size.width, waterMarkImage.size.height) let imageSize = self.size switch corner{ case .TopLeft: markFrame.origin = margin case .TopRight: markFrame.origin = CGPoint(x: imageSize.width - waterMarkImage.size.width - margin.x, y: margin.y) case .BottomLeft: markFrame.origin = CGPoint(x: margin.x, y: imageSize.height - waterMarkImage.size.height - margin.y) case .BottomRight: markFrame.origin = CGPoint(x: imageSize.width - waterMarkImage.size.width - margin.x, y: imageSize.height - waterMarkImage.size.height - margin.y) } // 开始给图片添加图片 UIGraphicsBeginImageContext(imageSize) self.drawInRect(CGRectMake(0, 0, imageSize.width, imageSize.height)) waterMarkImage.drawInRect(markFrame, blendMode: .Normal, alpha: alpha) let waterMarkedImage = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() return waterMarkedImage }} |
3，使用样例
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import UIKitclass ViewController: UIViewController { @IBOutlet weak var imageView: UIImageView! override func viewDidLoad() { super.viewDidLoad() //给图片添加水印 imageView.image = UIImage(named:"bg")? .waterMarkedImage(UIImage(named: "logo7")!,corner: .TopLeft, margin: CGPoint(x: 20, y: 20), alpha:1) } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() }} |
