ASINetworkQueue 中的第一个请求总是失败

Question

我正在开发一个应用程序，可让您从列表（在表格视图中）下载播客。 我使用 ASINetworkQueue 来允许同时进行多个下载。 下载发生在另一个类中（选项卡栏应用程序中的另一个视图控制器） 这个类是通过调用“addRequest:(url)”来通知的。

我面临的问题是，如果 ASINetworkQueue 为零，我正在创建一个新队列，并且我正在添加一个新请求，（仅调用 [queue go]在第一个）

但是，我的第一个请求从未开始。我在“requestDidStart”中有一个 NSLog，我发现它没有被调用。

从我的第二个请求开始，一切正常，但第一个请求仍然无法开始下载。

我的代码如下：

 -(void)downloadFile:(NSMutableDictionary*)objectDetails fromFeed:(NSString*)feedTitle;
{

 NSMutableDictionary *fileData = [objectDetails mutableCopy];
[fileData setObject:feedTitle forKey:@"fromFeed"];

if(networkQueue==nil)
{
    NSLog(@"------------------>Network queue was NIL. Creating...<------------------");
    self.networkQueue = [ASINetworkQueue queue];
    [self.networkQueue setDelegate:self];
    [self.networkQueue setRequestDidFinishSelector:@selector(requestFinished:)];
    [self.networkQueue setRequestDidStartSelector:@selector(requestDidStart:)];
    [self.networkQueue setRequestDidFailSelector:@selector(requestFailed:)];
    [self.networkQueue setQueueDidFinishSelector:@selector(queueFinished:)];
}



ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:[NSURL URLWithString:[objectDetails objectForKey:@"audio"]]];
if (request == nil) {
    NSLog(@"There was an error downloading the file");
    return;
}
[request setShouldContinueWhenAppEntersBackground:YES];
[request setDelegate:self];

//Find pathname for file.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentsDirectory = [paths objectAtIndex:0]; // Get documents folder
NSString *dataPath = [documentsDirectory stringByAppendingPathComponent:@"Downloads"];

//If Downloads folder doesnt exist, create it.
NSError *error;
if (![[NSFileManager defaultManager] fileExistsAtPath:dataPath])
    [[NSFileManager defaultManager] createDirectoryAtPath:dataPath withIntermediateDirectories:NO attributes:nil error:&error]; 

NSMutableString *filepath = [NSString stringWithFormat:@"%@/%@",
                             dataPath,[[objectDetails objectForKey:@"audio"] lastPathComponent]];
if([filepath pathExtension] == @"")
{
    NSLog(@"extension did not exist. assuming MP3");
    [filepath appendString:@".mp3"];
}

NSLog(@"Will attempt to download to \n%@",filepath);

[request setDownloadDestinationPath:filepath];
[request setShowAccurateProgress:YES];
[networkQueue setShowAccurateProgress:YES];
[request setDownloadProgressDelegate:self];


[fileData setObject:request forKey:@"request"];
[fileData setObject:[NSNumber numberWithLongLong:0.0] forKey:@"completed"];

//Add this to array that keeps track of downloads
if(!pendingDownloadsArray)
{

    pendingDownloadsArray = [[NSMutableArray alloc] init];

}
[pendingDownloadsArray addObject:fileData];
[fileData release];


[networkQueue addOperation:request];
//Add the request to the queue and start.
if ([networkQueue requestsCount]==1 ) {
    NSLog(@"------------------>>Only 1 request. Starting queue with %d objects<------------------",[networkQueue requestsCount]);
    [networkQueue go];
} 
 }

Answer 1

您不需要检查请求计数，

只需使用“networkqueue go”就足够了。