Question

我正在使用IOS sdk上传文件，在Wifi上工作正常，但有时候在大文件上使用3G时会出现以下错误

- (void)connection:(NSURLConnection*)connection didFailWithError:(NSError*)anError .....

“NSURLErrorDomain -1021请求正文流已耗尽”。

我知道我可以通过实现方法来覆盖这个问题：

- (NSInputStream*)connection:(NSURLConnection *)connection needNewBodyStream:(NSURLRequest *) request

所以我做到了。但是当这个方法调用我遇到didFailWithError时出现下一个错误“操作无法完成。无法分配内存”。

如果我向方法needNewBodyStream添加一些延迟，则此错误消失。有人可以解释一下这个延迟需要什么，我怎么能摆脱这个黑客？

这是我的代码：

- (void) startUpload    
{    
   NSInputStream* fileStream = [[NSInputStream alloc] initWithFileAtPath: sourcePath];

   [self.request setHTTPMethod:@"PUT"];

   [self.request setValue:[NSString stringWithFormat: @"%lu", fileSize] forHTTPHeaderField: @"Content-Length"];

   [self.request setHTTPBodyStream: fileStream];

   NSURLConnection* newConnection = [[NSURLConnection alloc] initWithRequest: self.request delegate: self startImmediately: YES];

   self.connection = newConnection;

   [newConnection release];
   [fileStream release];
}

#pragma mark NSURLConnectionDelegate

- (NSInputStream *) connection: (NSURLConnection *) aConnection needNewBodyStream: (NSURLRequest *) request
{
   [NSThread sleepForTimeInterval: 2];

   NSInputStream* fileStream = [NSInputStream inputStreamWithFileAtPath: sourcePath];

   if (fileStream == nil)
   {
       NSLog(@"NSURLConnection was asked to retransmit a new body stream for a request. Returning nil will cancel the connection.");
   }

   return fileStream;
}

NSURLConnection通过3G发生错误

0 个答案: