首先排除ios9 ? ATS的設(shè)置問(wèn)題。

1、SDWebImage可以正常加載HTTPS的圖片。

2、SDWebImage可以加載有些HTTP圖片。

3、SDWebImage不能加載有些HTTP的圖片，但是網(wǎng)頁(yè)上打開，或者UIWebView可以正常加載。

排除了所有可能的問(wèn)題。

找到這個(gè)答案：Stackflow

For some reason yourSDWebImagewasn’t persisting theuser-Agent

以下代碼貼上使用。即可加載部分不能加載的圖片。

NSString*userAgent=@"";userAgent=[NSStringstringWithFormat:@"%@/%@ (%@; iOS %@; Scale/%0.2f)",[[[NSBundlemainBundle]infoDictionary]objectForKey:(__bridgeNSString*)kCFBundleExecutableKey]?:[[[NSBundlemainBundle]infoDictionary]objectForKey:(__bridgeNSString*)kCFBundleIdentifierKey],[[[NSBundlemainBundle]infoDictionary]objectForKey:@"CFBundleShortVersionString"]?:[[[NSBundlemainBundle]infoDictionary]objectForKey:(__bridgeNSString*)kCFBundleVersionKey],[[UIDevicecurrentDevice]model],[[UIDevicecurrentDevice]systemVersion],[[UIScreenmainScreen]scale]];if(userAgent){if(![userAgent canBeConvertedToEncoding:NSASCIIStringEncoding]){NSMutableString*mutableUserAgent=[userAgent mutableCopy];if(CFStringTransform((__bridgeCFMutableStringRef)(mutableUserAgent),NULL,(__bridgeCFStringRef)@"Any-Latin; Latin-ASCII; [:^ASCII:] Remove",false)){userAgent=mutableUserAgent;}}[[SDWebImageDownloadersharedDownloader]setValue:userAgent forHTTPHeaderField:@"User-Agent"];}