Swift 的 PhotoSlider

PhotoSlider 是一个简单的照片滑块，可以通过滑动来删除滑块。

要求

Xcode 9+
Swift 4.0+
iOS 10+

安装

CocoaPods

PhotoSlider 通过 CocoaPods 提供。要安装它，只需将以下行添加到您的 Podfile 中

pod "PhotoSlider"

Carthage

Carthage 是 Cocoa 应用程序的分布式依赖项管理器。

$ brew update
$ brew install carthage

要将 PhotoSlider 集成到您的 Xcode 项目中，并使用 Carthage，请在 Cartfile 中指定它。

github "nakajijapan/PhotoSlider"

然后，运行以下命令构建 PhotoSlider 框架：

$ carthage update

用途

使用 ZoomingAnimationControllerTransitioning

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {

    var slider = PhotoSlider.ViewController(imageURLs: self.images)
    slider.currentPage = indexPath.row
    photoSlider.transitioningDelegate = self
    present(photoSlider, animated: true, completion: nil)

}

ZoomingAnimationControllerTransitioning

返回起始位置的 imageView

// MARK: ZoomingAnimationControllerTransitioning

func transitionSourceImageView() -> UIImageView {

    let indexPath = collectionView.indexPathsForSelectedItems?.first
    let cell = collectionView.cellForItem(at: indexPath!) as! ImageCollectionViewCell
    let imageView = UIImageView(image: cell.imageView.image)

    var frame = cell.imageView.frame
    frame.origin.y += UIApplication.shared.statusBarFrame.height

    imageView.frame = frame
    imageView.clipsToBounds = true
    imageView.contentMode = .scaleAspectFill

    return imageView

}

返回完成位置的 sourceImageView

func transitionDestinationImageView(sourceImageView: UIImageView) {

    guard let image = sourceImageView.image else {
        return
    }

    let indexPath = collectionView.indexPathsForSelectedItems?.first
    let cell = collectionView.cellForItem(at: indexPath!) as! ImageCollectionViewCell
    let statusBarHeight = UIApplication.shared.statusBarFrame.height

    // snip..

    sourceImageView.frame = frame

}

UIViewControllerTransitioningDelegate

// MARK: UIViewControllerTransitioningDelegate

func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    let animationController = PhotoSlider.ZoomingAnimationController(present: false)
    animationController.sourceTransition = dismissed as? ZoomingAnimationControllerTransitioning
    animationController.destinationTransition = self
    return animationController
}

func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    let animationController = PhotoSlider.ZoomingAnimationController(present: true)
    animationController.sourceTransition = source as? ZoomingAnimationControllerTransitioning
    animationController.destinationTransition = presented as? ZoomingAnimationControllerTransitioning
    return animationController
}

使用 UIModalTransitionStyle

选择 ZoomingAnimationController

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {

    var slider = PhotoSlider.ViewController(imageURLs: self.images)
    slider.modalPresentationStyle = .OverCurrentContext
    slider.modalTransitionStyle = UIModalTransitionStyle.CrossDissolve
    slider.index = indexPath.row
    self.presentViewController(slider, animated: true, completion: nil)

}

代理

您可以用以下事件处理：

可选 func photoSliderControllerWillDismiss(viewController: PhotoSlider.ViewController)
可选 func photoSliderControllerDidDismiss(viewController: PhotoSlider.ViewController)

多图加载器

PhotoSlider使用Kingfisher进行远程图片加载。如果您的项目使用SDWebImage，Kingfisher和SDWebImage之间不会共享图片缓存。在这种情况下，您可以使用自定义ImageLoader。默认的ImageLoader是Kingfisher。

以下是更改SDWebImage的方法。

首先，创建一个自定义的ImageLoader。

import PhotoSlider

class PhotoSliderSDImageLoader: PhotoSlider.ImageLoader {
    public func load(
        imageView: UIImageView?,
        fromURL url: URL?,
        progress: @escaping PhotoSlider.ImageLoader.ProgressBlock,
        completion: @escaping PhotoSlider.ImageLoader.CompletionBlock)
    {
        // Webp compatibility (optional)
        let WebPCoder = SDImageWebPCoder.shared
        SDImageCodersManager.shared.addCoder(WebPCoder)
        
        imageView?.sd_setImage(
            withURL: url,
            placeholderImage: nil,
            options: SDWebImageOptions.retryFailed,
            progress: { (receivedSize, totalSize) in
                progress(receivedSize, totalSize)
            },
            completed: { (image, _, _, _) in
                completion(image)
            }
        )
    }
}

然后，设置ImageLoader。

let slider = PhotoSlider.ViewController(imageURLs: images)
slider.modalPresentationStyle = .OverCurrentContext
slider.modalTransitionStyle = UIModalTransitionStyle.CrossDissolve
slider.index = indexPath.row
slider.imageLoader = PhotoSliderSDImageLoader()
present(slider, animated: true, completion: nil)