ASIHttpRequest的网络编程

// 自定义缓存设置
    ASIDownloadCache *imageCache = [[ASIDownloadCache alloc] init];
    //设置缓存路径
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentDirectory = [paths objectAtIndex:0];
    [self.imageCache setStoragePath:[documentDirectory stringByAppendingPathComponent:@"resource"]];
    [self.imageCache setDefaultCachePolicy:ASIOnlyLoadIfNotCachedCachePolicy];
    [self.imageCache clearCachedResponsesForStoragePolicy:ASICachePermanentlyCacheStoragePolicy];

//  设置请求
    self.request = [ASIHTTPRequest requestWithURL:self.imageUrl];
    [self.request setDelegate:self];
    [self.request setShouldContinueWhenAppEntersBackground:YES];
    [self.request setTimeOutSeconds:60.0f];
    
    [self.request setDownloadCache:imageCache];
    [self.request setCacheStoragePolicy:ASICachePermanentlyCacheStoragePolicy];
    [self.request setDownloadProgressDelegate:progressView];
    
// 下载队列
    ASINetworkQueue *networkQueue = [[ASINetworkQueue alloc] init];
    [networkQueue reset];
    [networkQueue setShouldCancelAllRequestsOnFailure:NO];
    networkQueue.showAccurateProgress = YES;

//  添加请求到下载队列
    [networkQueue addOperation:self.request];
//  执行下载    
    [networkQueue go];