ios - 在 Playground 中使用实时照片

Question

我已经在网上进行了大量搜索，但我目前正在尝试在 Playground 中使用“Live Photos”。我知道框架（PHLivePhoto），我只是不知道是否可以在 Playground 中使用它们，因为没有太多“导入”，因为似乎没有任何“实时照片”可用用于在线下载。有任何想法吗？

Answer 1

可以根据实际 Live Photo 的元素在 Playground 中制作和查看 PHLivePhoto 。

在 OS X 的Photos应用程序中，选择一张 Live Photo 并转到菜单

文件 > 导出 > 导出原始...

它将创建一个.JPG和一个.mov。

将这两个文件放到ResourcesPlayground 的文件夹中（菜单 View > Navigator > Show Project Navigator）。

获取这两个文件的 URL NSBundle（在我的示例中，文件是“IMG_0001.JPG”和“IMG_0001.mov”）：

let imgURL = NSBundle.mainBundle().URLForResource("IMG_0001", withExtension: "JPG")!
let movURL = NSBundle.mainBundle().URLForResource("IMG_0001", withExtension: "mov")!

并创建一个实际图像，我们将需要它用于 Live Photo 预览图像：

let prevImg = UIImage(named: "IMG_0001.JPG")!

导入必要的框架：

import Photos
import PhotosUI
import XCPlayground

并将 Playground 设置为异步模式：

XCPlaygroundPage.currentPage.needsIndefiniteExecution = true

现在我们将使用PHLivePhoto'srequestLivePhotoWithResourceFileURLs方法从我们的元素中创建一个 PHLivePhoto：

func makeLivePhotoFromItems(imageURL: NSURL, videoURL: NSURL, previewImage: UIImage, completion: (livePhoto: PHLivePhoto) -> Void) {
    PHLivePhoto.requestLivePhotoWithResourceFileURLs([imageURL, videoURL], placeholderImage: previewImage, targetSize: CGSizeZero, contentMode: PHImageContentMode.AspectFit) {
        (livePhoto, infoDict) -> Void in
        // for debugging: print(infoDict)
        if let lp = livePhoto {
            completion(livePhoto: lp)
        }
    }
}

然后我们这样调用：

makeLivePhotoFromItems(imgURL, videoURL: movURL, previewImage: prevImg) { (livePhoto) -> Void in
    // "livePhoto" is your PHLivePhoto object
}

例如，假设您希望 Playground 进行实时取景：

makeLivePhotoFromItems(imgURL, videoURL: movURL, previewImage: prevImg) { (livePhoto) -> Void in
    let rect = CGRect(x: 0, y: 0, width: 2048, height: 1536)
    let livePhotoView = PHLivePhotoView(frame: rect)
    livePhotoView.livePhoto = livePhoto
    XCPlaygroundPage.currentPage.liveView = livePhotoView
    livePhotoView.startPlaybackWithStyle(PHLivePhotoViewPlaybackStyle.Full)
}

请注意，由于无法与实时取景交互来开始播放实时照片，我们必须自己使用PHLivePhotoView'startPlaybackWithStyle方法来完成。

您可以通过在菜单中显示 Assistant Editor 来强制实时视图出现在 Playground 中

查看 > 助理编辑器 > 显示助理编辑器

注意：Playground 可能需要一些时间来创建 PHLivePhoto 并启动实时取景。

---

使用 Xcode 7.3b+，我们终于可以在 Playgrounds 中进行一些 UI 交互了。

我已经用一个简单的视图和 touchesBegan 对这个答案进行了改编，只需在控制台这样说时单击 LivePhoto：

import UIKit
import XCPlayground

import Photos
import PhotosUI

class PLView: UIView {

    let image: UIImage
    let imageURL: NSURL
    let videoURL: NSURL

    let liveView: PHLivePhotoView

    init(image: UIImage, imageURL: NSURL, videoURL: NSURL) {
        self.image = image
        self.imageURL = imageURL
        self.videoURL = videoURL
        let rect = CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height)
        self.liveView = PHLivePhotoView(frame: rect)
        super.init(frame: rect)
        self.addSubview(self.liveView)
    }

    func prepareLivePhoto() {
        makeLivePhotoFromItems { (livePhoto) in
            self.liveView.livePhoto = livePhoto
            print("\nReady! Click on the LivePhoto in the Assistant Editor panel!\n")
        }
    }

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        print("\nClicked! Wait for it...\n")
        self.liveView.startPlaybackWithStyle(.Full)
    }

    private func makeLivePhotoFromItems(completion: (PHLivePhoto) -> Void) {
        PHLivePhoto.requestLivePhotoWithResourceFileURLs([imageURL, videoURL], placeholderImage: image, targetSize: CGSizeZero, contentMode: .AspectFit) {
            (livePhoto, infoDict) -> Void in
            // This "canceled" condition is just to avoid redundant passes in the Playground preview panel.
            if let canceled = infoDict[PHLivePhotoInfoCancelledKey] as? Int where canceled == 0 {
                if let livePhoto = livePhoto {
                    completion(livePhoto)
                }
            }
        }
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}



XCPlaygroundPage.currentPage.needsIndefiniteExecution = true

let plview = PLView(image: UIImage(named: "IMG_0001.JPG")!,
                 imageURL: NSBundle.mainBundle().URLForResource("IMG_0001", withExtension: "JPG")!,
                 videoURL: NSBundle.mainBundle().URLForResource("IMG_0001", withExtension: "mov")!)

XCPlaygroundPage.currentPage.liveView = plview

plview.prepareLivePhoto()

---

Swift 3.0.2（Xcode 8.2.1）的相同示例：

import UIKit
import PlaygroundSupport
import Photos
import PhotosUI

class PLView: UIView {

    let image: UIImage
    let imageURL: URL
    let videoURL: URL

    let liveView: PHLivePhotoView

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    init(image: UIImage, imageURL: URL, videoURL: URL) {
        self.image = image
        self.imageURL = imageURL
        self.videoURL = videoURL
        let rect = CGRect(x: 0, y: 0, width: 300, height: 400)
        self.liveView = PHLivePhotoView(frame: rect)
        super.init(frame: rect)
        self.addSubview(self.liveView)
    }

    func prepareLivePhoto() {
        makeLivePhotoFromItems { (livePhoto) in
            self.liveView.livePhoto = livePhoto
            print("\nReady! Click on the LivePhoto in the Assistant Editor panel!\n")
        }
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        print("\nClicked! Wait for it...\n")
        self.liveView.startPlayback(with: .full)
    }

    private func makeLivePhotoFromItems(completion: @escaping (PHLivePhoto) -> Void) {
        PHLivePhoto.request(withResourceFileURLs: [imageURL, videoURL], placeholderImage: image, targetSize: CGSize.zero, contentMode: .aspectFit) {
            (livePhoto, infoDict) -> Void in

            if let canceled = infoDict[PHLivePhotoInfoCancelledKey] as? NSNumber,
                canceled == 0,
                let livePhoto = livePhoto
            {
                completion(livePhoto)
            }
        }
    }

}

let plview = PLView(image: UIImage(named: "IMG_0001.JPG")!,
                    imageURL: Bundle.main.url(forResource: "IMG_0001", withExtension: "JPG")!,
                    videoURL: Bundle.main.url(forResource: "IMG_0001", withExtension: "mov")!)

PlaygroundPage.current.needsIndefiniteExecution = true
PlaygroundPage.current.liveView = plview

plview.prepareLivePhoto()