Question

当尝试从indexPAth.row的URL加载图像时，出现索引超出范围错误。

我具有正确的结构模型，可以从Json响应中获取URL。而且我可以在调试器窗口中获取URL，但是一旦我尝试在cellForRowAt：中获取图像，那便是出现Fata错误的时候。

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return redditData.count
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = self.tableView.dequeueReusableCell(withIdentifier: "RedditTableCell", for: indexPath) as! RedditTableCell

        let post = redditData[indexPath.row]

        // uncomment this print statement and I get the fata error
        //print(post.data.preview?.images?[indexPath.row].source.url)   

        // uncomment this and in the debugger it will show the images URL path
        //print(post.data.preview?[0].source.url)  

        // each cell has only one   mainImage 
        print(post.data.preview?.images?[0].source?.url)  // prints the image url path, for each cell.
        cell.thumbnail.sd_setImage(with: URL(string: post.data.thumbnail!))
        cell.mainImage.sd_setImage(with: URL(string: (post.data.preview?.images?.source!.url)!)) 
        // images is an array [images]

        return cell
    }

这是调试器的输出：

https://www.reddit.com/r/all/.json
Optional("https://external-preview.redd.it/aF3ZkA26B3LsRG6ugjJTHAgn5uL_3y_iniPkFMGTZqY.jpg?auto=webp&amp;s=1554c0af19a4e1776a29878c4c0c1cb1c1324c15")
Optional("https://preview.redd.it/cy8jp6qvvb631.jpg?auto=webp&amp;s=cc5a0c15d130a4c54f33963ccce4cd1588871e85")
Optional("https://preview.redd.it/b39b3dgalb631.jpg?auto=webp&amp;s=19b137dc245a243acda7c6a08b7d7e3d5b2acda6")
2019-06-24 13:37:46.137915-0500 MyRedditBrowser[15273:1933069] Task <77A8D26A-6460-48A2-9140-381470ABB7DF>.<1> finished with error - code: -1002
2019-06-24 13:37:46.140059-0500 MyRedditBrowser[15273:1933066] Task <77A8D26A-6460-48A2-9140-381470ABB7DF>.<1> load failed with error Error Domain=NSURLErrorDomain Code=-1002 "unsupported URL" UserInfo={NSLocalizedDescription=unsupported URL, NSErrorFailingURLStringKey=default, NSErrorFailingURLKey=default, _NSURLErrorRelatedURLSessionTaskErrorKey=(
    "LocalDataTask <77A8D26A-6460-48A2-9140-381470ABB7DF>.<1>"
), _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <77A8D26A-6460-48A2-9140-381470ABB7DF>.<1>, NSUnderlyingError=0x6000016d0600 {Error Domain=kCFErrorDomainCFNetwork Code=-1002 "(null)"}} [-1002]

那么我最想念的是什么呢？有时我根本看不到任何NSURLError？

Answer 1

您在说

print(post.data.preview?.images?[indexPath.row].source.url)

如果images为空或其count小于indexPath.row+1，则会崩溃。因此，请事先做好条件检查。

if let count = post.data.preview?.images?.count, count > indexPath {

致命错误：索引超出范围UITableView indexPath.row

1 个答案: