Ios 内存警告解除分配viewcontroller?
我有一个mainIos 内存警告解除分配viewcontroller?,ios,memory-management,uiviewcontroller,didreceivememorywarning,Ios,Memory Management,Uiviewcontroller,Didreceivememorywarning,我有一个mainUIViewcontroller(vcMain),其中有两个UIViewcontroller子类。两个子类UIViewcontrollers(vcSub1/vcSub2)只显示一个图像和一些其他控件。vcSub1和vcSub2显示在UITabBarController中。 我实施了如下direceivememorywarning: vcMain: - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarnin
UIViewcontroller
(vcMain),其中有两个UIViewcontroller
子类。两个子类UIViewcontrollers
(vcSub1/vcSub2)只显示一个图像和一些其他控件。vcSub1和vcSub2显示在UITabBarController
中。
我实施了如下direceivememorywarning
:
vcMain:
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
if ([self isViewLoaded] == NO) {
// release the model, will be recreated in viewDidLoad
[_brain release], self.brain = nil;
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
if ([self isViewLoaded] == NO) {
// will be recreated in viewDidLoad, only exists in vcSub1
[self.zoomBrain release], [self setZoomBrain:nil];
_button = nil; // autoreleased, created programmatically
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
if ([self isViewLoaded] == NO) {
// nothing in here (yet)
}
}
vcSub1:
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
if ([self isViewLoaded] == NO) {
// release the model, will be recreated in viewDidLoad
[_brain release], self.brain = nil;
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
if ([self isViewLoaded] == NO) {
// will be recreated in viewDidLoad, only exists in vcSub1
[self.zoomBrain release], [self setZoomBrain:nil];
_button = nil; // autoreleased, created programmatically
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
if ([self isViewLoaded] == NO) {
// nothing in here (yet)
}
}
vcSub2:
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
if ([self isViewLoaded] == NO) {
// release the model, will be recreated in viewDidLoad
[_brain release], self.brain = nil;
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
if ([self isViewLoaded] == NO) {
// will be recreated in viewDidLoad, only exists in vcSub1
[self.zoomBrain release], [self setZoomBrain:nil];
_button = nil; // autoreleased, created programmatically
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
if ([self isViewLoaded] == NO) {
// nothing in here (yet)
}
}
当我第一次模拟内存警告时,一切似乎都正常
Received simulated memory warning.
-[AppDelegate applicationDidReceiveMemoryWarning:] [Line 81]
-[vcSub2 didReceiveMemoryWarning] [Line 102]
-[vcMain didReceiveMemoryWarning] [Line 73]
-[vcSub2 viewDidUnload] [Line 112]
-[vcMain viewDidUnload] [Line 65]
-[vcSub1 didReceiveMemoryWarning] [Line 150]
-[vcMain didReceiveMemoryWarning] [Line 73]
-[vcSub1 viewDidUnload] [Line 143]
-[vcMain viewDidUnload] [Line 65]
我可以一次又一次地这样做,没有问题。但是,如果我切换选项卡(从而重新加载视图)并再次模拟内存警告,我会得到以下结果:
Received simulated memory warning.
-[AppDelegate applicationDidReceiveMemoryWarning:] [Line 81]
-[vcSub2 didReceiveMemoryWarning] [Line 102]
-[vcMain didReceiveMemoryWarning] [Line 73]
-[vcSub1 didReceiveMemoryWarning] [Line 150]
-[vcMain didReceiveMemoryWarning] [Line 73]
-[vcSub1 viewDidUnload] [Line 143]
-[vcMain viewDidUnload] [Line 65]
*** -[vcSub1 isViewLoaded]: message sent to deallocated instance 0x614de80
info malloc history 0x614de80
显示实例是vcSub1 viewcontroller
Alloc: Block address: 0x0614de80 length: 192
Stack - pthread: 0xa0425540 number of frames: 21
0: 0x93f7f0a3 in malloc_zone_calloc
1: 0x93f7effa in calloc
2: 0x154a2d4 in class_createInstance
3: 0x13165d8 in +[NSObject(NSObject) allocWithZone:]
4: 0x13163da in +[NSObject(NSObject) alloc]
5: 0x2bf0 in -[AppDelegate application:didFinishLaunchingWithOptions:] at AppDelegate.m:47
6: 0x8dec89 in -[UIApplication _callInitializationDelegatesForURL:payload:suspended:]
7: 0x8e0d88 in -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:]
8: 0x8eb617 in -[UIApplication handleEvent:withNewEvent:]
9: 0x8e3abf in -[UIApplication sendEvent:]
10: 0x8e8f2e in _UIApplicationHandleEvent
11: 0x30b9992 in PurpleEventCallback
12: 0x13d3944 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__
13: 0x1333cf7 in __CFRunLoopDoSource1
14: 0x1330f83 in __CFRunLoopRun
15: 0x1330840 in CFRunLoopRunSpecific
16: 0x1330761 in CFRunLoopRunInMode
17: 0x8e07d2 in -[UIApplication _run]
18: 0x8ecc93 in UIApplicationMain
19: 0x28f9 in main at main.m:14
20: 0x2875 in start
我的vcSub1 viewcontroller解除分配的原因和方式?我认为您释放对象的次数太多了。假设您的属性是(保留),那么您在这里有一个bug:
[self.zoomBrain release]
[self setZoomBrain:nil];
第一行将释放放大镜
第二行将释放zoomBrain,然后将其设置为nil
你释放它两次-你只需要第二行。如果使用setter方法(即setZoomBrain:),则它会自动为您释放上一个zoomBrain
这同样适用于:
[_brain release];
self.brain = nil;
调用self.brain是另一种书写方式代码>-再次,发布将被调用两次
在每种情况下,您只需要第二行:
self.brain = nil;
谢谢读了你的答案后,我做了更多的研究,现在我明白了;)