在connectionDidFinishLoading连接释放的方法，会导致错误(connectio

测试要求，并得到官方的苹果开发者网站的响应例子。

https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/URLLoadingSystem/Tasks/UsingNSURLConnection.html

使用[连接释放在connectionDidFinishLoading方法，会导致错误：应该已经失效 - EXC_BAD_ACCESS

如果我注释行[连接释放]方法; 一切似乎工作，但我怕有内存泄漏的发生是因为连接不存在释放。

什么可能导致或如何避免这个问题？

@imlementation test
NSMutableData *dataStore=nil;

//example usage:
//[self registerToServer:@"http://testserver.com/registeruser.ashx" withUserName:@"john doe" withPassword:@"123456"];

-(void)registerToServer:(NSString*)urlstr withUserName:(NSString*)
ausername withPassword:(NSString*)apassword
{
  NSURL *url=[NSURL URLWithString:urlstr];
    NSMutableURLRequest *request=[NSMutableURLRequest requestWithURL:url cachePolicy:NSURLCacheStorageNotAllowed timeoutInterval:3.0f];
[request setHTTPMethod:@"POST"];
[request setValue:ausername forHTTPHeaderField:@"pass"];
[request setValue:apassword forHTTPHeaderField:@"username"];
NSURLConnection *connection=[NSURLConnection connectionWithRequest:request delegate:self];
[connection start];

if(connection)
    dataStore=[[NSMutableData data]retain];
}

- （无效）连接：（NSURLConnection的*）连接didReceiveData：（NSData的*）数据{[数据存储区appendData：数据]; }

- (void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[dataStore setLength:0];}

-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
NSLog(@"connection failed:%@ %@",
      [error localizedDescription],
      [[error userInfo]objectForKey:NSURLErrorFailingURLStringErrorKey]);

[connection release];
[dataStore release];
}

-(void)connectionDidFinishLoading:(NSURLConnection *)connection
  {
    //[connection release];   //WELL... I CANT COMMENT OUT THIS LINE!
    NSString *res=[[NSString alloc]initWithData:dataStore encoding:NSUTF8StringEncoding];

    NSLog(@"%@",res);
[dataStore release];
  }

创建使用工厂方法的连接。只有当你使用alloc/init ， new ， copy ，或retain你应该使用release 。在这种情况下，系统会释放对象对你的照顾。

更重要的是，使用ARC。