iphone - objective-c 中的内存问题

Question

我的应用程序试图使用某个东西的僵尸实例，但我不知道问题出在哪里。调用 (IBAction)addTag:sender 时始终出现异常。
我的堆栈跟踪如下:

2012-03-12 17:06:45.935 FavoriteTwitterSearches[3636:f803] -[__NSCFString addTag:]: unrecognized selector sent to instance 0x6a30d90
2012-03-12 17:06:45.943 FavoriteTwitterSearches[3636:f803] CRASH: -[__NSCFString addTag:]: unrecognized selector sent to instance 0x6a30d90
2012-03-12 17:06:45.947 FavoriteTwitterSearches[3636:f803] Stack Trace: (
    0   CoreFoundation                      0x013bc06e __exceptionPreprocess + 206
    1   libobjc.A.dylib                     0x0154dd0a objc_exception_throw + 44
    2   CoreFoundation                      0x013bdced -[NSObject doesNotRecognizeSelector:] + 253
    3   CoreFoundation                      0x01322f00 ___forwarding___ + 432
    4   CoreFoundation                      0x01322ce2 _CF_forwarding_prep_0 + 50
    5   CoreFoundation                      0x013bdec9 -[NSObject performSelector:withObject:withObject:] + 73
    6   UIKit                               0x000165c2 -[UIApplication sendAction:to:from:forEvent:] + 96
    7   UIKit                               0x0001655a -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61
    8   UIKit                               0x000bbb76 -[UIControl sendAction:to:forEvent:] + 66
    9   UIKit                               0x000bc03f -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 503
    10  UIKit                               0x000bb2fe -[UIControl touchesEnded:withEvent:] + 549
    11  UIKit                               0x0003ba30 -[UIWindow _sendTouchesForEvent:] + 513
    12  UIKit                               0x0003bc56 -[UIWindow sendEvent:] + 273
    13  UIKit                               0x00022384 -[UIApplication sendEvent:] + 464
    14  UIKit                               0x00015aa9 _UIApplicationHandleEvent + 8196
    15  GraphicsServices                    0x012a6fa9 PurpleEventCallback + 1274
    16  CoreFoundation                      0x013901c5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
    17  CoreFoundation                      0x012f5022 __CFRunLoopDoSource1 + 146
    18  CoreFoundation                      0x012f390a __CFRunLoopRun + 2218
    19  CoreFoundation                      0x012f2db4 CFRunLoopRunSpecific + 212
    20  CoreFoundation                      0x012f2ccb CFRunLoopRunInMode + 123
    21  GraphicsServices                    0x012a5879 GSEventRunModal + 207
    22  GraphicsServices                    0x012a593e GSEventRun + 114
    23  UIKit                               0x00013a9b UIApplicationMain + 1175
    24  FavoriteTwitterSearches             0x00001fab main + 187
    25  FavoriteTwitterSearches             0x00001ee5 start + 53
    26  ???                                 0x00000001 0x0 + 1
)
objc[3636]: EXCEPTIONS: finishing handler

支持文件/Main.m:

#import <UIKit/UIKit.h>

#import "AppDelegate.h"
void uncaughtExceptionHandler(NSException *exception);

int main(int argc, char *argv[])
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

    int retVal;
    @try {
    retVal = UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
    }
    @catch (NSException *exception) {
        NSLog(@"CRASH: %@", exception);
        NSLog(@"Stack Trace: %@", [exception callStackSymbols]);
    }
    @finally {
        [pool release];
    }
    return retVal;
}

Controller .m

#import "Controller.h"

@implementation Controller
- (id)init
{
    if (self != nil)
    {
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *dir = [paths objectAtIndex:0];
        filePath = [[NSString alloc] initWithString:[dir stringByAppendingPathComponent:@"tagsIndex.plist"]];
        NSFileManager *fileManager = [NSFileManager defaultManager];

        if ([fileManager fileExistsAtPath:filePath] == NO)
        {
            tags = [[NSMutableDictionary alloc] init];
        }
        else
        {
            tags = [[NSMutableDictionary alloc] initWithContentsOfFile:filePath];
        }

        buttons = [[NSMutableArray alloc] init];
        infoButtons = [[NSMutableArray alloc] init];
    }
    return self;
}

- (void)awakeFromNib
{
    for (NSString *title in tags)
        [self addNewButtonWithTitle:title];
}

- (void)refreshList
{
    for (UIButton *button in scrollView.subviews)
        [button removeFromSuperview];

    [infoButtons removeAllObjects];

    float buttonOffset = BUTTON_SPACING;

    for (UIButton *button in buttons)
    {
        CGRect buttonFrame = button.frame;
        buttonFrame.origin.x = BUTTON_SPACING;
        buttonFrame.origin.y = buttonOffset;
        buttonFrame.size.width = scrollView.frame.size.width - BUTTON_SPACING - BUTTON_HEIGHT;
        buttonFrame.size.height = BUTTON_HEIGHT;
        button.frame = buttonFrame;

        UIButton *infobutton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
        [infoButtons addObject:infobutton];

        buttonFrame = infobutton.frame;
        buttonFrame.origin.x = scrollView.frame.size.width - BUTTON_SPACING - SCROLLBAR_WIDTH;
        buttonFrame.origin.y = buttonOffset;
        infobutton.frame = buttonFrame;

        [infobutton
         addTarget:self action:@selector(infoButtonTouched:)
         forControlEvents:UIControlEventTouchUpInside];
        [scrollView addSubview:infobutton];

        buttonOffset += BUTTON_HEIGHT + BUTTON_SPACING;
    }
}

- (void)infoButtonTouched:sender
{
    int index = [infoButtons indexOfObject:sender];

    NSString *key = [[buttons objectAtIndex:index] titleLabel].text;
    tagField.text = key;

    NSString *value = [tags valueForKey:key];
    queryField.text = value;
}

- (IBAction)addTag:sender
{
    [tagField resignFirstResponder];
    [queryField resignFirstResponder];

    NSString *key = tagField.text;
    NSString *value = queryField.text;

    if (value.length == 0 || key.length == 0) return;

    if ([tags valueForKey:key] == nil)
        [self addNewButtonWithTitle:key];

    [tags setValue:value forKey:key];

    tagField.text = nil;
    queryField.text = nil;

    [tags writeToFile:filePath atomically:NO];
}

- (IBAction)clearTags:sender
{
    [tags removeAllObjects];
    [tags writeToFile:filePath atomically:NO];
    [buttons removeAllObjects];
    [self refreshList];
}

- (void)addNewButtonWithTitle:(NSString *)title
{
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [button setTitle:title forState:UIControlStateNormal];
    [button
     addTarget:self action:@selector(buttonTouched:)
     forControlEvents:UIControlEventTouchUpInside];
    [buttons addObject:button];

    [buttons sortUsingSelector:@selector(compareButtonTitles:)];
    [self refreshList];

    CGSize contentSize = CGSizeMake(
                                scrollView.frame.size.width,
                                buttons.count * (BUTTON_HEIGHT + BUTTON_SPACING) + BUTTON_SPACING);
    [scrollView setContentSize:contentSize];
}

- (void)buttonTouched:sender
{
    NSString *key = [sender titleLabel].text;
    NSString *search = [[tags valueForKey:key]
                        stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    NSString *urlString = [NSString stringWithFormat:
                           @"http://search.twitter.com/search?q=%@", search];
    NSURL *url = [NSURL URLWithString:urlString];
    [[UIApplication sharedApplication] openURL:url];
}
- (void)dealloc
{
    [filePath release];
    [tags release];
    [infoButtons release];
    [buttons release];
    [super dealloc];
}
@end

@implementation UIButton (sorting)
- (NSComparisonResult)compareButtonTitles:(UIButton *)button
{
    return [self.titleLabel.text caseInsensitiveCompare:button.titleLabel.text];
}
@end

Answer 1

[__NSCFString addTag:]: unrecognized selector sent to instance 表示您正在 NSString 类型的实例上调用方法 addTag:。

检查什么对象以及你的 IBAction 在你的 xib 中是如何连接的。如果一切正常，请尝试清理您的项目，重置您的模拟器，然后重试。

编辑:请将 NSLog 添加到您的 dealloc 中，以检查您的 Controller 是否未被释放。