NSURLCache不会清除iOS8中存储的响应

Question

这是我需要清除缓存并对URL进行新调用时调用的示例函数

- (void)clearDataFromNSURLCache:(NSString *)urlString
{
    NSURL *requestUrl = [NSURL URLWithString:urlString];
    NSURLRequest *dataUrlRequest = [NSURLRequest requestWithURL: requestUrl];

    NSURLCache * cache =[NSURLCache sharedURLCache];


    NSCachedURLResponse* cacheResponse =[cache cachedResponseForRequest:dataUrlRequest];

    if (cacheResponse) {
        NSString* dataStr = [NSString stringWithUTF8String:[[cacheResponse data] bytes]];
        NSLog(@"data str r= %@",dataStr);
        NSLog(@"url  str r= %@",[[[cacheResponse response] URL] absoluteString]);
        [cache storeCachedResponse:nil forRequest:dataUrlRequest];
        [NSURLCache setSharedURLCache:cache];
    }

    [[NSURLCache sharedURLCache] removeCachedResponseForRequest:dataUrlRequest];

    //Check if the respnase data has been removed/deleted from cache
    NSURLRequest *finalRequestUrlRequest = [NSURLRequest requestWithURL:requestUrl];
    NSURLCache * finalCache =[NSURLCache sharedURLCache];

    NSCachedURLResponse* finalcacheResponse =[finalCache cachedResponseForRequest:finalRequestUrlRequest];

    if (finalcacheResponse) {
        //Should not enter here
        NSString* finaldataStr = [NSString stringWithUTF8String:[[finalcacheResponse data] bytes]];
        NSLog(@"data str r= %@",finaldataStr);
        NSLog(@"url  str r= %@",[[[cacheResponse response] URL] absoluteString]);
    }
}

在iOS 6/7中,requestURL的响应被成功删除,但在iOS 8中它永远不会被删除.我已搜索但无法找到原因,这在iOS8中不起作用.

任何帮助将不胜感激…..

Answer 1

NSURLCache在iOS 8.0.x上被破坏 - 它根本不会清除缓存,因此它会不受限制地增长.有关详细调查,请参见http://blog.airsource.co.uk/2014/10/11/nsurlcache-ios8-broken/.缓存清除被固定在8.1测试版-但是removeCachedResponseForRequest:是不是.

removeCachedResponsesSinceDate: 确实可以在iOS 8.0上运行 - 一个为8.0添加的API,但尚未进入文档(它在API差异中).我不清楚它对任何人有什么用 - 当然你通常想做的是在特定日期之前删除缓存的响应.

removeAllCachedResponses 同样有效 - 但这是一个真正的大锤解决方案.