在 tableview 中显示下载的图像 [英] display downloaded images in tableview

问题描述

我正在 Swift 2.0 中制作一个应用程序，我在原型单元格中使用带有图像视图的表格视图.该应用程序从 facebook 服务器下载了一些图像，我想显示它们.这些图像都是从不同的 url 下载的，所以我正在使用一个程序来循环它们并下载，就像我使用名称从互联网上获取它们并显示一样，但我有点卡住了..

I'm making an app in Swift 2.0 and I'm using a table view with an image view in the prototype cell. The app downloads some images from the facebook server and I want to display them. The images are all downloaded from a different url, so I am using a program to loop trough them and download, just like I did with the names to get them from the internet and display, but I'm a little bit stuck..

 func fetchPicture(identifier: String, completion: (image: UIImage) -> Void)
 {
let url2 = NSURL (string: "http://graph.facebook.com/" + identifier + "/picture?type=normal")

 let urlRequest = NSURLRequest(URL: url2!)

 NSURLConnection.sendAsynchronousRequest(urlRequest, queue: NSOperationQueue.mainQueue()) { 
 (response, data, error) -> Void in
    if error != nil 
    {
        print(error)
    } 
    else 
    {

         if let pf = UIImage(data: data!)
          {
            dispatch_async(dispatch_get_main_queue())
             {
                     completion(image: pf)
                    self.tableView.reloadData()
             }
     }


   }
 }}

var images = [UIImage]()

let queue2 = dispatch_queue_create("images", DISPATCH_QUEUE_SERIAL)

dispatch_apply(newArray.count, queue2) { index in
    let identifier = newArray[index]
    fetchPicture(identifier) {
        image in dispatch_async(queue2) 
        {

        }
    }
}

我将单元格中的图像视图设置为等于变量图像"，因此基本上我需要执行类似 self.image = pf 的操作，但每个用户都需要不同.对于名称，我使用数组进行了此操作，但这不适用于我假设的图像..

I set the imageview in the cell equal to the variable 'image' so basically I will need to do something like self.image = pf but it needs to be different for each user. With names, I did this with an array, but this isn't working with images I assume..

帮助真的很感激伙计们！谢谢！

Help is really appreciated guys! Thanks!

推荐答案

您通常希望使用专门处理此类问题的框架.我不推荐使用 SDWebImage，它已经过时(没有 NSURLSession)，有很多未解决的问题并且不能很好地与 Swift 一起使用(没有可空性注释).

You would generally want to use a framework that specializes on that kind of stuff. I would not recommend using SDWebImage, it's outdated (no NSURLSession), has a lot of open issues and doesn't work well with Swift (no nullability annotations).

看看 iOS 平台上最新的两个库:

Take a look at those two libraries that are up to date with iOS platform:

• DFImageManager - 用 Objective-C 编写的高级框架，但具有可空性注释(适用于 Swift).这是一个事情列表，让它变得更好，比 SDWebImage.披露是我写的，意见可能有偏见.
• Kingfisher - 用 Swift 编写的轻量级库.与 SDWebImage 类似，但功能比 SDWebImage 和 DFImageManager 少得多.

• DFImageManager - advanced framework written in Objective-C but featuring nullability annotations (works great with Swift). Here's a list of things that make it better, than SDWebImage. Disclosure it's written by me, opinion might be biased.
• Kingfisher - lightweight library written in Swift. Similar to SDWebImage, but has much less features that SDWebImage and DFImageManager.

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