iphone - iAd AdBanner 内存泄漏问题(应用程序崩溃)

Question

我有一个带有列表/详细信息 View 的简单应用程序。在详细 View 中，我有 1 个 webview 并显示 1 个 iAd。当我在列表/详细信息 View 之间切换时，我的应用程序有时会崩溃。看来我的 iAd 代码有问题。请帮我修好它。我尝试使用 Leaks，但无法完全弄清楚。

下面是更新后的代码；

@interface DetailController : UIViewController <UIWebViewDelegate,ADBannerViewDelegate> {
    NSString *selectedTxt;
    IBOutlet UIWebView* webView;
    ADBannerView *adView_;
    BOOL bannerIsVisible;
}

@property(nonatomic,retain) NSString *selectedTxt;

@property(nonatomic,retain) UIWebView* webView;

@property (nonatomic,retain) ADBannerView *adView;
@property (nonatomic,assign) BOOL bannerIsVisible;

@end

实现

@implementation DetailController

@synthesize selectedTxt;
@synthesize webView,bannerIsVisible;
@synthesize adView = adView_;

/*
 // The designated initializer.  Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {
        // Custom initialization
    }
    return self;
}
*/

- (void) viewWillAppear:(BOOL)animated {

    bannerIsVisible = YES;
    adView_ = [[ADBannerView alloc] initWithFrame:CGRectZero];

    float origin_y;
    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) 
        origin_y = 360.0;
    else
        origin_y = self.view.frame.size.height;

    adView_.frame = CGRectMake(0.0,origin_y, adView_.frame.size.width, adView_.frame.size.height);

    if ( &ADBannerContentSizeIdentifierPortrait != NULL ) {
        adView_.requiredContentSizeIdentifiers = [NSSet setWithObject:ADBannerContentSizeIdentifierPortrait];
        adView_.currentContentSizeIdentifier = ADBannerContentSizeIdentifierPortrait;
    } else {
        adView_.requiredContentSizeIdentifiers = [NSSet setWithObject:ADBannerContentSizeIdentifier320x50];
        adView_.currentContentSizeIdentifier = ADBannerContentSizeIdentifier320x50;
    }

    adView_.delegate = self;

    [webView addSubview:adView_];

    [self.view bringSubviewToFront:adView_];
    self.bannerIsVisible=NO;

    [super viewWillAppear: animated];
}

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {

    //Set the title of the navigation bar
    //self.navigationItem.title = @"Selected Country";
    [super viewDidLoad];
}

/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return YES;
}
*/

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
    adView_.delegate = nil;
    self.adView = nil;
}


- (void)dealloc {
    adView_.delegate = nil;
    [adView_ release];
    [super dealloc];
}



- (void)bannerView:(ADBannerView *)banner didFailToReceiveAdWithError:(NSError *)error
{
    if (bannerIsVisible)
    {
        [UIView beginAnimations:@"animateAdBannerOff" context:NULL];
        // assumes the banner view is at the bottom of the screen.
        banner.frame = CGRectOffset(banner.frame, 0, 50); // if the banner is on top of the screen use -50
        [UIView commitAnimations];
        bannerIsVisible = NO;
    }
}

- (void)bannerViewDidLoadAd:(ADBannerView *)banner
{
    if (!bannerIsVisible)
    {
        [UIView beginAnimations:@"animateAdBannerOn" context:NULL];
        // assumes the banner view is offset -50 pixels so that it is not visible.
        banner.frame = CGRectOffset(banner.frame, 0, -50); // if the banner is on top of the screen use 50
        [UIView commitAnimations];
        bannerIsVisible = YES;
    }
}

- (BOOL)bannerViewActionShouldBegin:(ADBannerView *)banner willLeaveApplication:(BOOL)willLeave
{
    NSLog(@"Banner view is beginning an ad action");
    BOOL shouldExecuteAction = YES; // your application implements this method if you want it not fixed
    if (!willLeave && shouldExecuteAction)
    {
        // insert code here to suspend any services that might conflict with the advertisement
    }
    return shouldExecuteAction;
}



@end

错误日志

2011-12-17 20:33:23.142 MyApp[4382:207] ADBannerView: WARNING A banner view (0x6236190) has an ad but may be obscured. This message is only printed once per banner view.
[Switching to process 4382 thread 0x920f]
2011-12-17 20:34:14.154 MyApp[4382:207] -[__NSCFType bannerViewDidLoadAd:]: unrecognized selector sent to instance 0x62542f0
2011-12-17 20:34:14.195 MyApp[4382:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFType bannerViewDidLoadAd:]: unrecognized selector sent to instance 0x62542f0'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x00e025a9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x00f56313 objc_exception_throw + 44
    2   CoreFoundation                      0x00e040bb -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
    3   CoreFoundation                      0x00d73966 ___forwarding___ + 966
    4   CoreFoundation                      0x00d73522 _CF_forwarding_prep_0 + 50
    5   CoreFoundation                      0x00d72c7d __invoking___ + 29
    6   CoreFoundation                      0x00d72b51 -[NSInvocation invoke] + 145
    7   CoreFoundation                      0x00d73a04 ___forwarding___ + 1124
    8   CoreFoundation                      0x00d73522 _CF_forwarding_prep_0 + 50
    9   iAd                                 0x000149f9 -[ADDistributedMessagingCenter messagePort:receivedMessage:withData:] + 251
    10  iAd                                 0x00015012 ADMessagePortCallBack + 75
    11  CoreFoundation                      0x00db9f4c __CFMessagePortPerform + 396
    12  CoreFoundation                      0x00de3944 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
    13  CoreFoundation                      0x00d43cf7 __CFRunLoopDoSource1 + 215
    14  CoreFoundation                      0x00d40f83 __CFRunLoopRun + 979
    15  CoreFoundation                      0x00d40840 CFRunLoopRunSpecific + 208
    16  CoreFoundation                      0x00d40761 CFRunLoopRunInMode + 97
    17  GraphicsServices                    0x033ff1c4 GSEventRunModal + 217
    18  GraphicsServices                    0x033ff289 GSEventRun + 115
    19  UIKit                               0x00300c93 UIApplicationMain + 1160
    20  MyApp                     0x00002440 main + 102
    21  MyApp                     0x000023d1 start + 53
)
terminate called after throwing an instance of 'NSException'
[Switching to process 4382 thread 0x207]

Answer 1

您没有发布 iAd 实例。

1. 为 iAd 添加一个实例变量
2. 确保在卸载 View 时将其委托(delegate)设置为 nil。
3. 确保在卸载 View 时释放

在您的 DetailController 接口(interface)声明 (.h) 中；

@interface DetailController ...
{
    ...
    //note, we are using an instance variable with the trailing underscore
    ADBannerView *adView_;
}
//note, we are using an accessor without that trailing underscore - those are 
//glued together using the synthesize mechanics within the implementation
@property (nonatomic,retain) ADBannerView *adView;
...
@end

在您的 DetailController 实现中 (.m)；

@implementation DetailController

//this will glue the instance variable with our property accessor
@sythesize adView = adView_;
...

-(void)viewDidLoad
{
     [super viewDidLoad];
     //retained by alloc/init, hence no need for using the retain by the accessor
     adView_ = [[ADBannerView alloc] initWithFrame:CGRectZero];

     //note, in case you want this adbanner to be initialized at a different point,
     //like for example in viewWillAppear that you have to consider its former instance.
     //to be on the safe side, you could prefix the above init with a [adView release];
     ...
}

-(void)viewDidUnload
{
    [super viewDidUnload];
    //as always, make sure the delegate is invalidated
    adView_.delegate = nil;
    //use accessor mechanics to release and invalidate for convenience
    self.adView = nil;
}

-(void)dealloc
{
    //to be on the safe side, make sure the adview is released even if 
    //viewDidUnload was not called 
    //e.g. nested viewControllers omitting viewDidUnload pass on

    //as always, make sure the delegate is invalidated
    adView_.delegate = nil;
    //do NOT use accessor mechanics within init or dealloc for safety reasons
    [adView_ release];
    [super dealloc];
}
@end