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你们中的任何人都可以发布代码片段，关于处理多个的示例教程

使用 cocoa Touch 框架来自同一个 viewController 的 NSURLConnections....

感谢您未来的所有帮助......

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2 回答 2

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我使用 NSMutableDictionary 处理了多个 NSUrlConnections，它跟踪特定 NSURLConnection 应该将其结果保存到哪个 NSMutableData 实例。

在我的课开始时，我定义：

NSMutableDictionary *dataDictionary;

然后在我的 loadData 方法中，我有：

        // Create the request
    NSURLRequest *theRequest=[NSURLRequest requestWithURL:[NSURL URLWithString:currentCam]
                                              cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
                                          timeoutInterval:30];

    // create the connection with the request
    // and start loading the data
    NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
    if (theConnection) {

        NSMutableData *receivedData = receivedData = [[NSMutableData alloc] init];

        //keep track of this connection by adding it to subViewDictionary and dataDictionary with appropriate objects.
        [dataDictionary setObject:receivedData forKey:[theConnection description]];
    } 

    else {

        NSLog(@"ERROR DOWNLOADING WITH NSURLCONNECTION");
    }

    [theConnection release];

我使用 [theConnection description] 作为我的键，并使用 MSMutableData 的一个实例作为我字典中的对象，因此稍后我可以查找哪个实例与特定连接一起使用。如果你不这样做，你可能会遇到数据损坏的问题（多个连接都可以将它们的数据保存到同一个变量中）。

然后，我定义了以下 NSURlConnection 委托方法：

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSMutableData *)data
{
    //look up in dictionary to find out which recievedData instance to use.
    NSMutableData *theReceivedData = [dataDictionary objectForKey:[connection description]];

    // Append the new data to receivedData.
    [theReceivedData appendData:data];
}


- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
        //Lookup in the dictionary to find the correct instance of recievedData to put image into.  
    NSMutableData *theReceivedData = [dataDictionary objectForKey:[connection description]];
    [theReceivedData setLength:0];
    [activityIndicator stopAnimating];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    // inform the user that there was an error
    NSLog(@"Connection failed! Error - localizedDescription:%@ NSURLErrorFailingURLStringErrorKey:%@",
          [error localizedDescription],
          [[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);


    NSMutableData *theReceivedData = [dataDictionary objectForKey:[connection description]];
    [theReceivedData release];

    //remove keys for this connection since it did not load.
    [dataDictionary removeObjectForKey:[connection description]];   
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{

    //look up correct instance of recievedData in teh dictionary for this connection
    NSMutableData *theReceivedData = [dataDictionary objectForKey:[connection description]];

    NSLog(@"Succeeded! Received %d bytes of data",[theReceivedData length]);

    //---do stuff with data here//  

    [theReceivedData release];
}

对于单个连接，这里有一个关于 NSURlConnection 的很好的教程。我的代码基于它添加了 NSMutableDictionary 来跟踪每个 NSUrlConnection 和每个 NSMutableData 实例。

我希望这是有道理的并且是有帮助的！

于 2010-12-15T23:48:14.473 回答
0

请参阅此链接以获取答案。它用 asihttp 封装了 nsurlconnection，让你的生活更轻松。

ASIHTTP 是否支持多线程？

于 2010-09-30T11:36:49.323 回答