遇到一个编译报错：
Escaping closure captures non-escaping parameter ‘onCompletion‘
代码如下：
func fetchRecentPhotos(completion: (PhotosResult) -> Void)
{
let url = recentPhotosURL()
let request = URLRequest(url: url as URL)
let task = session.dataTask(with: request)
{
(data, response, error) -> Void in
let result = self.processRecentPhotosRequest(data: data as NSData?, error: error as NSError?)
completion(result)
}
task.resume()
}
这是由于completion导致的，默认闭包completion是@nonescaping的,只需要声明成@escaping即可。
func fetchRecentPhotos(completion: @escaping (PhotosResult) -> Void)
Swift: Escaping closure captures non-escaping parameter 'onCompletion'
原文：https://www.cnblogs.com/fengyaoyao/p/12830168.html