ios 带有 NSOperation 的异步 NSURLConnection
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Asynchronous NSURLConnection with NSOperation
提问by nameless
I want to do NSURLConnectionin background mode,because it response is having much data.Forums are telling to use Apple's finite length coding to use in didEnterBackground.
but I want to avoid it.instead of it I use following code through NSOperationwith NSInvocationas, but it is not working.connectToServeris having NSURLConnectionoperation.any help please?didReceiveData,didReceiveResponsedelegate methods are not called?
我想NSURLConnection在后台模式下做，因为它的响应有很多数据。论坛告诉使用 Apple 的有限长度编码在didEnterBackground. 但我想避免。相反的是我通过使用下面的代码NSOperation用NSInvocation的，但它不工作。connectToServer正在NSURLConnection手术。请帮忙吗？didReceiveData，didReceiveResponse委托方法没有被调用？
NSOperationQueue *queue = [NSOperationQueue new];
NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self
selector:@selector(connectToServer)
object:nil];
[queue addOperation:operation];
[operation release];
[queue autorelease];
-(void)connectToServer
{
NSURL *url = [NSURL URLWithString:@"http://www.google.com"];
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url];
NSURLConnection *theConnection = [[[NSURLConnection alloc] initWithRequest:theRequest delegate:self] autorelease];
if( theConnection )
{
webData = [[NSMutableData data] retain];
}
else
{
NSLog(@"theConnection is NULL");
}
}
回答by Nyx0uf
This kind of question was asked a zillion time. Delegates are not getting called because as of iOS 4 operations are started on a secondary thread. The thread probably exits before the delegates are called that's all.
这种问题被问了无数次。由于 iOS 4 操作是在辅助线程上启动的，因此不会调用委托。线程可能在调用委托之前退出，仅此而已。
Keep the connection on the main thread and handle the data in a background thread using GCD.
保持主线程上的连接并使用 GCD 在后台线程中处理数据。
I'v wrote about all this stuff here : http://cocoaintheshell.com/2011/04/nsurlconnection-synchronous-asynchronous/
我在这里写了所有这些东西：http: //cocoaintheshell.com/2011/04/nsurlconnection-synchronous-asynchronous/
EDIT : Updated link.
编辑：更新链接。
回答by Danra
Apple provides QHTTPOperation, which does just what you want, encapsulates an NSURLConnectionwithin an NSOperation, for a single request. You can find it in Apple's sample code.
Apple 提供了QHTTPOperation，它可以满足您的要求，将一个 , 封装NSURLConnection在 , 中NSOperation，用于单个请求。您可以在 Apple 的示例代码中找到它。
QHTTPOperationis actually a subclass of QRunLoopOperationwhich lets you encapsulate logic which depends on run-loop callbacks in an NSOperation.
QHTTPOperation实际上是它的一个子类，QRunLoopOperation它允许您封装依赖于 NSOperation 中运行循环回调的逻辑。
The 3rd party ASIHTTPRequestis a similar popular solution, AFAIK it is no longer maintained though.
第 3 方ASIHTTPRequest是一个类似的流行解决方案，但 AFAIK 它不再被维护。
回答by Barlow Tucker
Look at the sendAsynchronousRequest:queue:completionHandler: method documented here in Apple's Documentation. It allows asynchronous requests with NSURLConnection.
查看Apple 文档中记录的 sendAsynchronousRequest:queue:completionHandler: 方法。它允许使用 NSURLConnection 进行异步请求。
Note this requires iOS5 or higher
请注意，这需要 iOS5 或更高版本
