Swift获取屏幕快照

// 获取屏幕快照
    private func screenShot() -> UIImage{
        let window = UIApplication.shared.keyWindow!
        UIGraphicsBeginImageContext(window.size)
        
        // 绘图
        window.drawHierarchy(in: window.bounds, afterScreenUpdates: false)
        
        // 从图形上下文获取图片
        let image = UIGraphicsGetImageFromCurrentImageContext()!

        UIGraphicsEndImageContext()
        
        return image
    }