工作问题小记 navigation push和popviewcontroller dealloc问题

事件，在instruments检查内存泄漏时发现其中一个viewcontroller在navigation做pop操作后未做dealloc，导致内存泄漏

push操作代码如下：

    ViewController_leaveAMessage *leaveMessage = [[ViewController_leaveAMessage
alloc]
initWithNibName:@"ViewController_leaveAMessage"
bundle:nil];
    leaveMessage.toId =
self.friendRS.userId;

    [self.navigationController
pushViewController:leaveMessage animated:YES];
    [leaveMessage
release];

pop操作后viewcontroller记述理应为0，从而调用dealloc。但是这断点后发现pop后未调用dealloc，说明该viewcontroller在其他地方还有引用。可是冲上面代码看出，正常情来说不该出该问题。后在push操作前后加log查看retainCount，发现该viewcontroller在push后retainCount增加了6，push其他viewcontroller其retainCount仅增加5.

其后逐条删除该viewcontroller中得viewdidload方法中得代码发现，其中因在viewdidload中执行

    timer = [NSTimer
scheduledTimerWithTimeInterval:0.3
target:self
selector:@selector(showLblTimeRecorderOrPlayer)
userInfo:nil
repeats:YES];
导致该viewcontroller得retainCount在push操作后多加 1 。         总：timer应在pop前invalidate。navigation得push操作在操作中就会执行相应viewcontroller得viewdidiload。