问题描述
由于循环引用，代码是否会崩溃？
Does the code crash, because of a circular reference?
MenuController: UIViewController
- (id)initWithNibName:
{...
TabsController *tabs = [[TabsController alloc] initWithNibName:@"TabsController" bundle:nil];
self.tab = tabs;
....
}
//button pressed:
- (IBAction)showPrefFromMenu:(id)sender {
// todo change delegate!?
tab.tabDelegate = self;
[self presentModalViewController:tab animated:YES];
//[tab release];
}
// delegate method:
-(void)myViewDismissed {
....
NSLog(@"tab references: %d", [tab retainCount]) ;
[self dismissModalViewControllerAnimated:YES];//crash
...
}
模态/子类：
TabsController : UIViewController <...>
- (IBAction)dismissTabs:(id)sender {
...
NSLog(@"dismissTabs: sender: %@",sender);
[self.tabDelegate myViewDismissed];
}
我看到self.tabDelegate是MenuController实例，并且该代码需要请关闭并取消分配TabsController。
As I see the self.tabDelegate is the MenuController instance and on that code want do dismiss and deallocate the TabsController.
虽然在[self.tabDelegate myViewDismissed]之后不再有任何代码;但是如果它不能执行，因为它被解除分配，可能是程序集Ret还是什么指令无法执行？返回声明。
Although it isn't any more code after [self.tabDelegate myViewDismissed]; but if it would be than couldn't execute, because it is deallocated, maybe the assembly Ret or what instruction can't be executed? the return statement.
我会尝试将代理或任何更好的解决方案分开？
I will try to separate the delegate or any better solution?
编辑：
崩溃是典型的：EXC_BAD_ACCESS（代码= 1，地址= 090）
大会看起来像这样：
ldr r1，[r4，r0]
The crash is the typical one: EXC_BAD_ACCESS(code=1,address=090)the Assembly looks like this:ldr r1, [r4, r0]
Edit2：
改变了一下代码，因为在模拟器4.3中没有崩溃，但在5.0它是，现在这里是当前代码：
changed a bit the code, because in simulator 4.3 doesn't crash, but at 5.0 it is, now here is the current code:
- (IBAction)showTab:(id)sender {
tab.tabDelegate = self;
if (SYSTEM_VERSION_LESS_THAN(@"5.0")) {
[self presentModalViewController:tab animated:YES];
}
else{
NSLog(@"Executing presentViewController (ios>= 5.0)");
[self presentViewController:tab animated:true completion: nil];
}
}
-(void)delegateCallback {
if (SYSTEM_VERSION_LESS_THAN(@"5.0")) {
[self dismissModalViewControllerAnimated:NO];
}
else{
NSLog(@"Executing dismissViewControllerAnimated (ios>= 5.0)");
[self dismissViewControllerAnimated:TRUE completion: nil];//crash
}
}
Edit3截图：
UIWindowController过渡：fromViewController：toViewController：didEndSeelctor行崩溃，原因是：没有parentViewController：
这里的人找到了解决方案，：但在NDA下
UIWindowController transition:fromViewController:toViewController:didEndSeelctor line is crashing, due to: no parentViewController:https://devforums.apple.com/message/451045Guys here found a solution, : https://github.com/ideashower/ShareKit/issues/254 but in under NDA
编辑已解决以重新调整到PushviewController for ios 5.0+
a heplfull链接：
Edit solved to revrite to PushviewController for ios 5.0+a heplfull link: https://stackoverflow.com/a/7767767/529543
- (IBAction)presentViewController:(id)sender {
tab.tabDelegate = self;
if (SYSTEM_VERSION_LESS_THAN(@"5.0")) {
[self presentModalViewController:tab animated:FALSE];
}
else{
NSLog(@"Executing presentViewController (ios>= 5.0) [tab retainCount]: %d " ,[tab retainCount]);
// store parent view to able to restore the state:
parentView = self.view.superview;
// init a navigation controler and set up:
navigationController=[[UINavigationController alloc] initWithRootViewController:self];
[self.view removeFromSuperview];
[myAppDelegate.window addSubview:navigationController.view]; ///appDelegate is delegate of ur Application
navigationController.navigationBar.hidden =true;
[navigationController pushViewController:tab animated:YES];
}
}
并弹出：
-(void)infoViewDismissed {
if (SYSTEM_VERSION_LESS_THAN(@"5.0")) {
[self dismissModalViewControllerAnimated:NO];
}
else{
NSLog(@"Executing dismissViewControllerAnimated (ios>= 5.0) ");
[navigationController popToRootViewControllerAnimated:false];
[navigationController.view removeFromSuperview];
[parentView addSubview:self.view];
}
}
我已解决了我的问题，一个非常丑陋的模式，但是功能...还被告知放弃对ios3的支持:)我不喜欢运行时的GUI架构切换。
I have solved my problem, in a very ugly mode, but is functional...Also told to drop the support for ios3 :) I don't like the GUI architecture switch at runtime at all.
推荐答案
你的问题有点难以理解，但我知道你有一个保留周期：
Your question is a little difficult to understand, but I gather you have a retain-cycle:
ObjectA retains ObjectB
ObjectB retains ObjectA
并且两个对象都没有被释放？
and neither object gets deallocated?
tabDelegate的属性应为：
Your property for the tabDelegate should read:
@property (nonatomic, assign) id tabDelegate;
// ^^^^^^-This is the important bit, this stops the retain cycle.
这篇关于在ios5上dismissViewControllerAnimated崩溃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！