DDGScreenShot—图片擦除功能

小鱼儿 2021-04-27 15:04 479阅读 0赞

### 写在前面 ###

图片擦除功能，也是运用图片的绘制功能，
将图片绘制后，拿到相应的图片。当然，有一涨底图更明显

## DDGScreenShot 所有功能演示 ##

#  #

### 实现代码如下 ###

/**
         ** 用手势擦除图片
         - imageView --传图片
         - bgView --截图背景
         */
        public func clearImage(imageView: UIImageView?, rect: CGRect) -> UIImage? {
            if imageView == nil {
                return nil
            }
            //开启一个位图上下文
            UIGraphicsBeginImageContextWithOptions((imageView?.bounds.size)!, false, 0.0)
            //把ImageView内容渲染到上下文当中
            let imageCtx = UIGraphicsGetCurrentContext()
            imageView?.layer.render(in: imageCtx!)
            //擦除上下文当中某一块区域
            imageCtx!.clear(rect)
            //得到新图片
            let newImage = UIGraphicsGetImageFromCurrentImageContext()
            //关闭上下文
            UIGraphicsEndImageContext()
    
            return newImage
        }
        
        ### 当然你也可以把图片绘制过程放入子线程中，再次就不列举了

### 具体用法 ###

//底部图片
        private lazy var bottomImageView: UIImageView = {
            let imageView = UIImageView()
            imageView.image = UIImage(named: "image")
            imageView.frame = CGRect(x: 0, y: 100, width: width, height: width)
            self.view.addSubview(imageView)
            imageView.isUserInteractionEnabled = true
            return imageView
        }()
        //要擦除的图片
        private lazy var clearImageView: UIImageView = {
            let imageView = UIImageView()
            imageView.image = UIImage(named: "logo")
            imageView.frame = CGRect(x: 0, y: 100, width: width, height: width)
            imageView.isUserInteractionEnabled = true
            self.view.addSubview(imageView)
            return imageView
        }()
        override func viewDidLoad() {
            super.viewDidLoad()
            self.view.backgroundColor = UIColor.white
            self.bottomImageView.isUserInteractionEnabled = false
            let pan = UIPanGestureRecognizer(target: self, action: #selector(DDGClearImageView.clearPan(pan:)))
            self.clearImageView.addGestureRecognizer(pan)
        }
        @objc func clearPan(pan: UIPanGestureRecognizer) {
            //获取当前手指的点
            let imageView = pan.view as! UIImageView
            let clearPan = pan.location(in: imageView)
            //擦除区域的大小
            let rect = CGRect(x: clearPan.x - 15, y: clearPan.y - 15, width: 30, height: 30)
            let newImage = DDGManage.share.clearImage(imageView: imageView, rect: rect)
            
            imageView.image = newImage
        }
    
    ### 是不是很好用

### 结束语 ###

此代码已经上传到githup[DDGScreenShot](https://github.com/dudongge/DDGScreenShot)
[link](https://github.com/dudongge/DDGScreenShot)
当然这只是这个库的功能的一小部分
想看更多功能，可以去github上下载，如果对您有帮助，希望您不吝给个star.