Swift4.0版-H5页面实现长按保存图片
- 刚开始拿到需求还是比较尴尬的,不会啊,没做过啊,是不是就尴尬了
- 随即想了一下,好像微信里好多H5页面都有这样的功能
- 然后查阅了一下相关资料,发现两行核心代码
//获取长按所在点let urlString = "document.elementFromPoint(\(touchPoint.x), \(touchPoint.y)).src"//根据该点的参数获取对应图片的链接let saveUrl = webView.stringByEvaluatingJavaScript(from: urlString)复制代码
下面来一起啊看一下完整的代码步骤
首先给UiWebView加一个长按手势
//添加长按手势let longPressGes = UILongPressGestureRecognizer(target: self, action: #selector(longPressedGesture(_:)))//一定要遵循代理longPressGes.delegate = selfwebView.addGestureRecognizer(longPressGes)复制代码
实现代理方法
//不实现该代理方法,长按无效//MARK: 手势代理方法extension SIWebViewController : UIGestureRecognizerDelegate{ func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool { return true }}复制代码 接着在手势响应方法里面实现相应的功能
注意:
- 一定要判断手势的state属性
- 判断saveUrl是否是一个nil值
@objc func longPressedGesture(recognizer: UILongPressGestureRecognizer){ if recognizer.state != .began { return } let touchPoint = recognizer.location(in: webView) //核心代码 let urlString = "document.elementFromPoint(\(touchPoint.x), \(touchPoint.y)).src" if let saveUrl = webView.stringByEvaluatingJavaScript(from: urlString) { //判断图片的链接是否为空,长度是否为o if saveUrl.characters.count == 0 { return } addAlertAction(saveUrl) }}复制代码 调用保存图片功能按钮
fileprivate func addAlertAction(imageStr: String){ let alertV = UIAlertController() let saveAction = UIAlertAction(title: "保存图片", style: .default) { (alertV) in self.saveImageToDisk(imageStr) } //取消保存不作处理 let cancelAction = UIAlertAction(title: "取消", style: .cancel, handler: nil) alertV.addAction(saveAction) alertV.addAction(cancelAction) controller.present(alertV, animated: true, completion: nil)}复制代码 使用SDWebImage保存图片
//保存图片 fileprivate func saveImageToDisk(_ imageStr: String){ guard let imageUrl = URL(string: imageStr) else { return } let sdManager = SDWebImageManager.shared() var image : UIImage! if (sdManager?.diskImageExists(for: imageUrl))! { //先从缓存中查找图片 image = sdManager?.imageCache.imageFromDiskCache(forKey: imageUrl.absoluteString) }else{ //缓存中没有图片在进行网络下载 let data = try! Data(contentsOf: imageUrl) image = UIImage(data: data) } //保存图片到相册中 UIImageWriteToSavedPhotosAlbum(image, self, #selector(self.image(_:didFinishSavingWithError:contextInfo:)), nil) }复制代码 最后是一个保存成功与否的回调方法
@objc func image(_ image: UIImage, didFinishSavingWithError: NSError?, contextInfo: AnyObject){ if didFinishSavingWithError != nil { MBProgressHUD.show(string: "请开启访问相册权限后使用此功能", inView: self.view) } else { MBProgressHUD.show(string: "图片保存成功", inView: self.view) }}复制代码 以上如有不妥之处还望多多指正