Question

（注意：我之前在项目的上下文中提交了这个问题，但我现在已经在测试项目中重新创建了崩溃。任何帮助告诉我我做错了什么都会受到赞赏。）

从另一个模态viewcontroller调用ABPeoplePicker时发生崩溃。具体来说，主窗口有一个NavController，它加载myVC。 myVC然后加载一个包含我的控制器的模态NavController，然后调用ABPeoplePicker。在此演示程序中，在ABPeoplePicker运行之前，无需用户干预。

如果您使用人员选择器中的搜索框，然后选择其中一个结果人员，则会发生崩溃。（如果你使用模拟器，你需要在运行程序之前在Contacts中添加一个人。）程序返回，但在解雇两个模态VC期间，我得到一个断言错误崩溃。它每次都出现在iphone，ipad和模拟器上。这似乎是很正常的事情，所以我发现很难相信这是一个真正的错误。崩溃消息是：

断言失败 - [ABMembersSearchDisplayController setActive：animated：]， /SourceCache/UIKit_Sim/UIKit-1448.69/UISearchDisplayController.m:589 2011-01-31 13:51:11.903 testcrasher2 [26044：207] * 由于未被捕获而终止应用程序例外 'NSInternalInconsistencyException'，原因：'搜索内容导航控制器之间不能改变 -setActive：YES和-setActive：NO'

所以为了演示，在一个新的Xcode iPhone Window应用程序中，我修改了didFinishLaunchingWithOptions来调用我的控制器。然后我按如下方式创建两个VC。（注意，您需要将Addressbook框架添加到目标。）这是整个程序......

AppDelegate.didFinishLaunchingWithOptions：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    
    myViewController *detailViewController = [[myViewController alloc] init];

    // Set the navigation controller as the window's root view controller and display.
    UINavigationController * navController = [[UINavigationController alloc] initWithRootViewController: detailViewController];

    self.window.rootViewController = navController;
    [self.window makeKeyAndVisible];

    [detailViewController release];
    [navController release];

    return YES;
}

myViewController.h：

@interface myViewController :  UIViewController<addDelegate>{
 }
@end

myViewController.m：

#import "myViewController.h"
#import "AddNewViewController.h"        

@implementation myViewController

- (void)controllerDidFinish:(addNewViewController *)controller  {
    [self dismissModalViewControllerAnimated:YES];
}

-(void) viewWillAppear:(BOOL)animated  {
    [super viewWillAppear: animated];

    addNewViewController *addController = [[addNewViewController alloc] init];
    addController.delegate = self;

    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:addController];
    [self presentModalViewController:navController animated:YES];

    [navController release];
    [addController release];
}

@end

AddNewViewController.h：

#import <AddressBookUI/AddressBookUI.h>

@protocol addDelegate;

@interface addNewViewController : UIViewController  < ABPeoplePickerNavigationControllerDelegate> {
    id <addDelegate> delegate;  
}
    @property(nonatomic, assign) id <addDelegate> delegate;
@end


@protocol addDelegate <NSObject> 
    - (void)controllerDidFinish:(addNewViewController *)controller ; 
@end

AddNewViewController.m：

#import "AddNewViewController.h"

@implementation addNewViewController

@synthesize delegate;

-(void) viewDidAppear:(BOOL)animated {  
    ABPeoplePickerNavigationController * peoplepicker =  [[ABPeoplePickerNavigationController alloc] init] ;    
    peoplepicker.peoplePickerDelegate = self;
    [self presentModalViewController:peoplepicker animated:YES];
    [peoplepicker release];
}

#pragma mark AddressBook delegate methods

- (void)peoplePickerNavigationControllerDidCancel: (ABPeoplePickerNavigationController *)peoplePicker { 
    [self dismissModalViewControllerAnimated:YES];
}

- (BOOL)peoplePickerNavigationController: (ABPeoplePickerNavigationController *)peoplePicker
      shouldContinueAfterSelectingPerson:(ABRecordRef)person {
    [self.delegate controllerDidFinish:self ];  
    return NO;   //EDIT:  This MUST be YES or it will crash (see answer below)
}

- (BOOL)peoplePickerNavigationController:(ABPeoplePickerNavigationController *)peoplePicker 
      shouldContinueAfterSelectingPerson:(ABRecordRef)person
      property:(ABPropertyID)property 
      identifier:(ABMultiValueIdentifier)identifier {
    return NO;
}

@end

Answer 1

原来这是一个真正的错误。确实如果你在用户点击搜索中的某个人时对你的ABPeoplePicker进行双重ModalVC解雇，你就会遇到这种崩溃。幸运的是，有一个简单的解决方法：在委托中输入YESContinueAfterSelectingPerson。当你同时解雇选择器时，无论你返回YES还是NO都没关系，它不会继续，但是NO会崩溃，YES则不会。（与我原来的帖子答案相同：Weird crash in ABPeoplePicker）

Answer 2

该错误实际上在您的代码中。花了几分钟才找到它，我会尽力解释。

您 ABPeoplePickerNavigationController 目前以模态呈现。
您点击搜索栏并输入一些东西。
您点击了某个人的姓名。

这里发生了什么，是ABPeoplePickerNavigationController询问其代表（您的addNewViewController）是否应该在选择一个人后继续。在等待您回复的同时，您突然调用自己的协议方法（在myViewController中）尝试关闭模式addNewViewController。由于ABPeoplePickerNavigationController仍处于打开状态，你已经超越了自己。

将ABPeoplePickerNavigationControllerDelegate方法的实现更改为：

- (BOOL)peoplePickerNavigationController: (ABPeoplePickerNavigationController *)peoplePicker
      shouldContinueAfterSelectingPerson:(ABRecordRef)person {
    // This line is new.
    [self.navigationController dismissModalViewControllerAnimated:YES];
    [self.delegate controllerDidFinish:self];
    return NO;
}

你的崩溃将会消失。当你在UIViewControllers和UINavigationControllers层上处理图层时，你必须非常小心地按照你提出的相反顺序来解雇它们。

当从另一个模态视图控制器调用时，ABPeoplePicker崩溃并且都被解雇了

2 个答案: