UIAlertViewDelegate类“自我”实例在按下按钮之前得到dealloc'd [英] UIAlertViewDelegate class "self" instance gets dealloc'd before button gets pressed

问题描述

我一直在寻找这个问题的解决方案几天，并且发现了一些类似的帖子，但似乎没有人发布一个明确的答案，如何阻止我正在使用的实例获得dealloc'd 。希望我只是错过了，或者有人可以帮助我停止摧毁我的大脑..

I have been searching for a solution to this issue for a few days and have found some similar posts, but no one seems to have posted a definitive answer to how to stop the instance i'm working with from getting dealloc'd. hopefully I just missed it, or someone can help me stop wracking my brain..

我有一个班级（ LKNetworking ）声明它符合 UIAlertViewDelegate 协议。目前它是 NSObject 的子类，但是我已经尝试了 UIResponder 但是产生了同样的问题。

I have a class (LKNetworking) which is declaring that it conforms to the UIAlertViewDelegate protocol. Currently it is a subclass of NSObject, however I have tried UIResponder but either produces the same issue.

问题是我创建了一个UIAlert视图并将委托设置为 self 。 UIAlert视图显示OK，但是调用它的 LKNetworking 类实例立即被释放（如我在NSLOG中所示），当我单击按钮时，消息得到发送到解除分配的实例（LKNetworking alertView：clickedButtonAtIndex：]：发送到解除分配的实例0x6e5ce40的消息）

Issue is that I create a UIAlert view and set the delegate to self. the UIAlert view shows OK, but then the LKNetworking Class instance that called it gets instantly dealloc'd (as I show in NSLOG) and when I click a button, the message gets sent to a deallocated instance (LKNetworking alertView:clickedButtonAtIndex:]: message sent to deallocated instance 0x6e5ce40)

所以，我试图在.h文件中创建一个属性as例如：

SO, I have tried to create a property in the .h file as such:

@property (strong, nonatomic) LKNetworking *strongNetworkingProperty

然后我尝试将我的UIAlertView的委托设置为strongNetworkingProperty ivar，消息似乎无处可去，所以没有好处..

I then try to set my UIAlertView's delegate to the strongNetworkingProperty ivar and the message seems to go nowhere, so thats no good..

我看到一些答案，人们说将警报视图委托设置为 nil ，但是由于我需要根据用户的选择做出相应的行动，因此打败了我的整个目的..

I saw some answers where people say to set the alert views delegate to nil, but that defeats my entire purpose since I need to act accordingly in response to the users selection..

这里是 LKNetworking 调用警报的方法委托方法：

here is the sample code of the LKNetworking method where the alert is called and the delegate method:

-(void)checkGameServerVersion: (float) serverGameVersion {
    if (serverGameVersion == GAMEVER) {
        NSLog(@"matched");
        // Continue flow here..
    } else {
        NSLog(@"not matched");
        //Game version does not match, end game, force upgrade 
        UIAlertView *oldVersion = [[UIAlertView alloc]initWithTitle:@"Ugrade Required" message:@"A new game version is available, Please update your game and try again." delegate:self cancelButtonTitle:@"Quit" otherButtonTitles: nil];
        [oldVersion show];
    }
}

-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    NSLog(@"button = %d",buttonIndex);
    if (buttonIndex == 0 ) {
        NSLog(@"pressed button 0, quitting gam");
    }
}
@end

任何建议都会很大赞赏！

Any suggestions would be greatly appreciated!

谢谢

推荐答案

如果你想让你的LKNetworking留下来一些东西需要保持对它的引用。那个东西可以是LKNetworking对象本身。创建警报视图时设置strongNetworkingProperty = self。这将创建一个保留周期，以防止系统取消分配LKNetworking对象。然后在alertView：clickedButtonAtIndex：中，将strongNetworkingProperty设置为nil以打破保留周期。

If you want your LKNetworking to stay around, something needs to keep a reference to it. That something can be the LKNetworking object itself. Set strongNetworkingProperty = self when you create the alert view. This creates a retain cycle that prevents the system from deallocating the LKNetworking object. Then in alertView:clickedButtonAtIndex:, set strongNetworkingProperty to nil to break the retain cycle.

这篇关于UIAlertViewDelegate类“自我”实例在按下按钮之前得到dealloc'd的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！