Question

我正在开发一款涉及从网络服务器下载数据的iPhone应用程序。除了方法connection:willCacheResponse:永远不会被调用之外，一切正常。但其他人如connection:didReceiveResponse:，connection:didReceiveData:，connection:didFailWithError:，connectionDidFinishLoading:一切正常。我建立了如下连接：

- (void)makeConnection
{
    NSURL *url = [NSURL URLWithString:@"http://www.abc.com"];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestReturnCacheDataElseLoad timeoutInterval:60];
    [request setHTTPMethod:@"POST"];
    NSString *postString = [NSString stringWithFormat:@"%@", string];
    [request setValue:[NSString stringWithFormat:@"%d", [postString length]] forHTTPHeaderField:@"Content-length"];
    [request setHTTPBody:[postString dataUsingEncoding:NSUTF8StringEncoding]];
    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
}

- (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse
{
    NSCachedURLResponse *newCachedResponse = cachedResponse;
    NSDictionary *newCachedResponseUserInfo = [NSDictionary dictionaryWithObject:[NSDate date] forKey:@"Cached Date"];
    newCachedResponse = [[NSCachedURLResponse alloc] initWithResponse:[cachedResponse response] data:[cachedResponse data] userInfo:newCachedResponseUserInfo storagePolicy:[cachedResponse storagePolicy]];

    return newCachedResponse;
}

我也尝试将政策更改为NSURLRequestUseProtocolCachePolicy，但没有任何帮助。还尝试在

中设置一个断点

- (NSCachedURLResponse *)connection:(NSURLConnection *)connection willCacheResponse:(NSCachedURLResponse *)cachedResponse

但没有发生任何事。我错过了什么吗？提前谢谢。

Answer 1

connection：willCacheResponse：仅在响应包含Cache-Control标头时被调用，根据Apple’s documentation:

委托接收连接：willCacheResponse：仅针对支持缓存的协议的消息。

连接：将永远不会调用willCacheResponse

1 个答案: