Objective C - 因保留周期而丢失

Question

关闭我的 VC 后，我注意到我并没有从内存中释放所有内容。我对如何找到我的保留周期感到非常迷茫。我使用的是 NSTimer 和 NSNotificationCenter，但我确保在退出前使 Observers 无效并移除，并且确保使用弱委托。

我的保留周期还会发生在其他什么地方？在动画块中？像这样？

 [UIView animateWithDuration:.1 delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
                self.setListTableViewVertConst.constant = 0;
                self.setListTableViewHeightConst.constant = 264;
            } completion:^(BOOL finished) {

            }];

使用 GCD 时，我确保使用 weakSelf。

__weak typeof(self) weakSelf = self;
            dispatch_async(dispatch_get_main_queue(), ^{
                [weakSelf.remotePasswordTextField resignFirstResponder];
            });

感谢您的帮助。

编辑：

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    //Send the room code to be displayed on the respective view controllers. 
    if ([segue.identifier isEqualToString:@"toSetListRoomVC"]) {
        SetListRoomViewController *setListVC = segue.destinationViewController;
        setListVC.roomCode = self.roomCodeTextField.text;
    }

}

viewWIllApear

[super viewWillAppear:YES];


    self.socket = [[SocketKeeperSingleton sharedInstance]socket];
    self.socketID = [[SocketKeeperSingleton sharedInstance]socketID];

    NSString *roomCodeAsHost = [[SocketKeeperSingleton sharedInstance]hostRoomCode];
    /////////HOST/////////
    if ([[SocketKeeperSingleton sharedInstance]isHost]) {

        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(receiveHostSongAddedNotification:)
                                                     name:kQueueAdd
                                                   object:nil];

        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(receiveUserJoinedNotification:)
                                                     name:kUserJoined
                                                   object:nil];

        NSLog(@"User is the host of this room");
        self.isHost = YES;
        [self viewForNoCurrentArtistAsHost];
        self.roomCodeLabel.text = roomCodeAsHost;

        if (!self.hostQueue) {
            self.hostQueue = [[NSMutableArray alloc]init];
        }
        if (!self.hostCurrentArtist) {
            self.hostCurrentArtist = [[NSMutableDictionary alloc]init];
        }

        if (!self.player) {
            self.player = [[AVPlayer alloc]init];
        }
        if (!self.timer) {
            self.timer = [[NSTimer alloc]init];
        }
    }

    ///////NOT HOST///////
    else {
        // Add a notifcation observer and postNotification name for updating the tracks.
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(receiveQueueUpdatedNotification:)
                                                     name:kQueueUpdated
                                                   object:nil];

        //Add a notifcation observer and postNotification name for updating current artist.
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(receiveCurrentArtistUpdateNotification:)
                                                     name:kCurrentArtistUpdate
                                                   object:nil];

        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(receiveOnDisconnectNotification:)
                                                     name:kOnDisconnect
                                                   object:nil];

        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(receiveHostDisconnectNotification:)
                                                     name:kHostDisconnect
                                                   object:nil];


        //Add some animations upon load up. Purple glow and tableview animation.
        double delay = .4;
        [self purpleGlowAnimationFromBottomWithDelay:&delay];
        [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationBottom];

        //Set Current artist, if there is one.
        NSDictionary *currentArtist = [[SocketKeeperSingleton sharedInstance]currentArtist];
        [self setCurrentArtistFromCurrentArtist:currentArtist];


        //Set the current tracks, if there is one.
        NSArray *setListTracks = [[SocketKeeperSingleton sharedInstance]setListTracks];
        if (setListTracks) {
            self.tracks = setListTracks;
        }
    }
}

表格视图

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if (tableView.tag == 1) {
        if (self.isHost) {
            return [self.hostQueue count];
        }
        else return [self.tracks count];
    }
    else return [self.searchTracks count];
}

-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

Answer 1

在此代码示例中，您没有将 __weak 用于 self

 [UIView animateWithDuration:.1 delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
                self.setListTableViewVertConst.constant = 0;
                self.setListTableViewHeightConst.constant = 264;
            } completion:^(BOOL finished) {

            }];

但是，乍一看，这似乎并没有创建保留循环。您发布的代码似乎没有，所以它可能在其他地方。你确定你有保留周期吗？

无论如何，请尝试 instrumenting 您的应用程序。可能会有帮助。

Answer 2

我注意到您在一些评论中使用了 "popOut" 这个词，所以我假设您使用的是导航控制器。

如果是这种情况，您的视图控制器将由其嵌入的导航控制器保留，不会被释放。导航控制器需要保存对您的 VC 的引用（参见 UINavigationController.viewControllers），以便当您在层次结构中弹出 top/next VC 时它可以返回到它。

这是预期的行为。

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