将图片从URL保存到库中，重命名并使用Swift共享

Question

我想从我自己的iOS应用程序将图像共享到Instagram，我在整个项目中都使用翠鸟来下载和缓存图像，并在UIImageViews中显示它们，但这次我想做一些不同的事情。

基本上，我从API得到了一个带有图像url的响应，我想

1. 使用URL将图像下载到库

对于使用的objective-C，有很多问题

UIImageWriteToSavedPhotosAlbum 

但我用的是Swift。

2. 使用.igo扩展名重命名(instagram独占)

不确定如何进行，取决于数字1。

3. 然后我可以分享它，做一些类似的事情

   let image = UIImage(named: "downloadedImage")
   let objectsToShare: [AnyObject] = [ image! ]
   let activityViewController = UIActivityViewController(activityItems: objectsToShare, applicationActivities: nil)
   activityViewController.popoverPresentationController?.sourceView = self.view
   
   activityViewController.excludedActivityTypes = [ UIActivityTypeAirDrop, UIActivityTypePostToFacebook ]
   
   self.presentViewController(activityViewController, animated: true, completion: nil)
   

或者我可以使用instagram挂钩：

instagram://library?LocalIdentifier=(localID)

专门针对Swift的相关文档很少。我该怎么办？我只需要朝着正确的方向努力。

Answer 1

听起来你已经知道如何使用翠鸟并从URL中检索UIImage了。因此，我要提供的是将图像保存到documents目录并检索以共享的信息。

检索正确的目录URL

func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let documentsDirectory = paths[0]
return documentsDirectory
}

将图像保存到该目录

func saveImage (image: UIImage, filename: String ){
print("Saving image with name (filename)")
if let data = UIImagePNGRepresentation(image) {
let fullURL = getDocumentsDirectory().appendingPathComponent(filename)
try? data.write(to: fullURL)
}
}

从目录检索图像

func loadImageFromName(name: String) -> UIImage? {
print("Loading image with name (name)")
let path = getDocumentsDirectory().appendingPathComponent(name).path
let image = UIImage(contentsOfFile: path)
if image == nil {
print("missing image at: (path)")
}
return image
}

共享图像

func share(shareText shareText:String?,shareImage:UIImage?){
var objectsToShare = [AnyObject]()
if let shareTextObj = shareText{
objectsToShare.append(shareTextObj)
}
if let shareImageObj = shareImage{
objectsToShare.append(shareImageObj)
}
if shareText != nil || shareImage != nil{
let activityViewController = UIActivityViewController(activityItems: objectsToShare, applicationActivities: nil)
activityViewController.popoverPresentationController?.sourceView = self.view
present(activityViewController, animated: true, completion: nil)
}else{
print("There is nothing to share")
}
}

如何使用

let img: UIImage = UIImage() // Replace this with your image from your URL
saveImage(image: img, filename: "newImage.igo") //This is where you change your extension name
let newImage: UIImage = loadImageFromName(name: "newImage.igo") //Retrieve your image with the correct extension
share(shareText: "Image going to Instagram", shareImage: newImage) //Present Activity VC.

正如DFD所指出的，你可以从共享VC中排除某些项目，只允许你需要的东西。

Answer 2

在我的导航控制器中，我有一个UIBarButtonItem设置为System项"Action"。然后我创建了以下IBAction代码：

@IBAction func shareImage(_ sender: UIBarButtonItem) {
let context = CIContext()
let final = context.createCGImage(imgFinished, from: imgFinished.extent)
let shareImage = UIImage(cgImage: final!)
let vc = UIActivityViewController(activityItems: [shareImage], applicationActivities: [])
vc.excludedActivityTypes =  [
UIActivityType.airDrop,
UIActivityType.assignToContact,
UIActivityType.addToReadingList,
//UIActivityType.copyToPasteboard,
//UIActivityType.mail,
//UIActivityType.message,
//UIActivityType.openInIBooks,
//UIActivityType.postToFacebook,
//UIActivityType.postToFlickr,
UIActivityType.postToTencentWeibo,
//UIActivityType.postToTwitter,
UIActivityType.postToVimeo,
UIActivityType.postToWeibo,
UIActivityType.print,
//UIActivityType.saveToCameraRoll
]
present(vc,
animated: true,
completion: nil)
vc.popoverPresentationController?.sourceView = self.view
vc.completionWithItemsHandler = {(activity, success, items, error) in
}
}

excludedActivityTypes列表是一个完整/详尽的可用UIActivityTypes列表，这些列表是从代码完成或命令单击UIActivity类型并遍历生成的结构中收集的。我取消注释那些我希望排除的内容，但将它们保留在中，以便将来快速参考。这会给你想要的弹出窗口。