NSURLConnection didFailWithError没有调用？ [英] NSURLConnection didFailWithError not called?

问题描述

为什么当指定的URL不存在图像时，是否没有调用FailWithError？例如：

  NSURLRequest * request = [NSURLRequest requestWithURL：[NSURL URLWithString：@http://www.google.com /images/someImageIknowDoesntExist.jpg] 
 cachePolicy：NSURLRequestReturnCacheDataElseLoad 
 timeoutInterval：10.0]; 
 
 urlConnection = [[NSURLConnection alloc] initWithRequest：request delegate：self]; 
  

不触发didFailWithError。如何获得通知，我尝试连接的URL没有图像？

解决方案

响应中的状态代码当您获得连接时，将为404：didReceieveResponse：方法。错误方法仅在获取URL时出现实际错误（如网络故障或主机不存在等））才被调用。

Why, when an image does not exist at a specified URL, does didFailWithError not get called? For example:

NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.google.com/images/someImageIknowDoesntExist.jpg"] 
                     cachePolicy:NSURLRequestReturnCacheDataElseLoad
                             timeoutInterval:10.0];

        urlConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self];

Does not trigger didFailWithError. How can I get notified that there is no image at the url I try to connect to?

解决方案

The status code in the response will be 404 when you get the connection:didReceieveResponse: method. The error method only gets called if there was an actually error fetching the URL (like the network went down, or the host doesn't exist, etc).

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