iphone - 更改 Timer 的时间间隔

Question

这是我的问题：例如，是否可以scheduledTimerWithTimeInterval:2在 ViewDidLoad 10 秒后增加“3”的示例。例如，从此：

[NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(createNewImage) userInfo:nil repeats:YES];

对此：

[NSTimer scheduledTimerWithTimeInterval:3 target:self selector:@selector(createNewImage) userInfo:nil repeats:YES];

谢谢你对不起我的英语我法语：/

Answer 1

像这样递归地重新安排计时器：

float gap = 0.50;

[NSTimer scheduledTimerWithTimeInterval:gap target:self selector:@selector(onTimer) userInfo:nil repeats:NO];

-(void) onTimer {
    gap = gap + .05;
    [NSTimer scheduledTimerWithTimeInterval:gap target:self selector:@selector(onTimer) userInfo:nil repeats:NO];
}

========

或者根据如何在更改时间间隔的值时更新我的​​ NSTimer

使其无效：

[myTimer invalidate];

然后用新的时间创建一个新的。您可能还必须先将其设置为零。

myTimer = nil;
myTimer = [NSTimer scheduledTimerWithTimeInterval:mySlider.value 
                                           target:self 
                                         selector:@selector(myMethod) 
                                         userInfo:nil 
                                          repeats:YES];

Answer 2

用于setFireDate:重新安排计时器。您需要跟踪 ivar 中的计时器。例如：

@property (nonatomic, readwrite, retain) NSTimer *timer;

@synthesize timer=timer_;

- (void)setTimer:(NSTimer *)aTimer {
  if (timer_ != aTimer) {
    [aTimer retain];
    [timer_ invalidate];
    [timer_ release];
    timer_ = aTimer;
  }

- (void)dealloc {
  [timer_ invalidate];
  [timer_ release];
}

...

self.timer = [NSTimer scheduledTimerWithTimeInterval:...];

...

self.timer.fireDate = [NSDate dateWithTimeIntervalSinceNow:3]; // reschedule for 3 seconds from now