Iphone 无效NSTimer不工作

Iphone 无效NSTimer不工作,iphone,objective-c,sdk,nstimer,stringwithformat,Iphone,Objective C,Sdk,Nstimer,Stringwithformat,我已经创建了一个计时器,其中我将剩余时间转换为格式为“mm:ss”的字符串,并且当时间的字符串值为00:00时,我希望使计时器无效。由于某些原因,它不起作用,即使在我记录剩余时间时,我看到的值具有正确的格式,因此我不知道为什么从未输入“countTime:”中的“if”分支 有人能帮忙吗 -(id) init { if(self = [super init]) { NSDate *date = [[NSDate alloc] init]; self.int

我已经创建了一个计时器,其中我将剩余时间转换为格式为“mm:ss”的字符串,并且当时间的字符串值为00:00时,我希望使计时器无效。由于某些原因,它不起作用,即使在我记录剩余时间时,我看到的值具有正确的格式,因此我不知道为什么从未输入“countTime:”中的“if”分支

有人能帮忙吗

-(id) init {
    if(self = [super init]) {
        NSDate *date = [[NSDate alloc] init];
        self.intervalLength = date;
        [date release];

        NSString *timeRem = [[NSString alloc]init];
        self.timeRemaining = timeRem;
        [timeRem release];


        formatter = [[NSDateFormatter alloc] init];
        [formatter setDateFormat:@"mm:ss"];
        notification = [NSNotification notificationWithName:@"timer" object:self];
        notificationForEnd = [NSNotification notificationWithName:@"timerFinished" object:self];
        NSMutableDictionary *info = [[NSMutableDictionary alloc] init];
        [info setObject:formatter forKey:@"format"];
        [info setObject:notification forKey:@"notification"];
        [info setObject:notificationForEnd forKey:@"notificationEnd"];
        NSTimer *timer = [[NSTimer alloc] init];
        timer = [[NSTimer alloc] init];
        timer = [NSTimer timerWithTimeInterval:1.0 target:self selector:@selector(countTime:) userInfo:info repeats:YES];
        self.intervalTimer = timer;
    }
    return self;
}

-(void) startIntervalCountDown {
    runLoop = [NSRunLoop currentRunLoop];
    [runLoop addTimer:self.intervalTimer forMode:NSDefaultRunLoopMode];
}

-(void) countTime:(NSTimer*)timer {
    if(self.timeRemaining == @"00:00") {
        [timer invalidate];
        timer = nil;
        [[NSNotificationCenter defaultCenter] postNotification:[[timer userInfo] objectForKey:@"notificationEnd"]];
    }
    d = [self.intervalLength dateByAddingTimeInterval: -1.0];
    self.intervalLength = [d copy];
    self.timeRemaining = [[[timer userInfo] objectForKey:@"format"] stringFromDate:d];  
    [[NSNotificationCenter defaultCenter] postNotification:[[timer userInfo] objectForKey:@"notification"]];

您正在比较指针相等,而不是字符串相等。你想要

[self.timeRemaining isEqualToString:@"00:00"]