NSTimer暂停不起作用 [英] NSTimer Pause not working

问题描述

我设置了三个按钮，分别是开始，停止，暂停.并提供了NSTimer控件以进行计算.启动停止按钮可以很好地给我启动和停止时间，但是 pause 按钮不能给我准确的时间.它实际上是暂停时间..但是再次启动它会添加已暂停的时间定时显示[ay.我在开始5秒钟后暂停，等待5秒钟，然后按开始...它应该显示5 ...但显示10..

I have setup three buttons with start,stop,pause. and given controls to NSTimer to calculates.start stop button works fine gives me the start and stop time but pausebutton does not gives me accurate time .it actually pause time ..but start again it adds the paused timed and disp[ay. supoose i pause at 5 second of start and wait for 5 sec then press start...it should display 5 ...but displaying 10..

-(void)start:(NSTimer *)timer
{
  if(_timer==nil)
  {
    startDate =[NSDate date];

    _timer=[NSTimer scheduledTimerWithTimeInterval:0.25 target:self selector:@selector(timer:) userInfo:nil repeats:YES];
  }

  if(_timer!=nil)
  { 
    float pauseTime = -1*[pauseStart timeIntervalSinceNow];

    [_timer setFireDate:[previousFireDate initWithTimeInterval:pauseTime sinceDate:previousFireDate]];
  }

}

-(void)timer:(NSTimer *)timer
{
  NSInteger secondsSinceStart = (NSInteger)[[NSDate date] timeIntervalSinceDate:startDate];

  NSInteger seconds = secondsSinceStart % 60;
  NSInteger minutes = (secondsSinceStart / 60) % 60;
  NSInteger hours = secondsSinceStart / (60 * 60);
  NSString *result = nil;
  if (hours > 0) 
  {
    result = [NSString stringWithFormat:@"%02d:%02d:%02d", hours, minutes, seconds];
  }
  else 
  {
    result = [NSString stringWithFormat:@"%02d:%02d", minutes, seconds];        
  }

  label.text=result;

  NSLog(@"time interval -> %@",result);
}

-(void)stop
{
  if(_timer!=nil)
  {
    endDate = [NSDate date];
 NSLog(@"endate%@",endDate);

     NSTimeInterval interval = [endDate timeIntervalSinceDate:startDate];
NSLog(@"total time %f",interval);
    [_timer invalidate];
    _timer = nil; 
  startDate=nil;
  }
}

-(void)pause:(NSTimer *)timer
{
  pauseStart = [NSDate dateWithTimeIntervalSinceNow:0];

  previousFireDate = [_timer fireDate];

  [_timer setFireDate:[NSDate distantFuture]];
}

推荐答案

我创建了这个

I have created this applicaion on mac os. I think you can understand the logic and even copy this with minor changes...as for UILabel.

在.h

@interface AppDelegate : NSObject <NSApplicationDelegate>

@property (assign) IBOutlet NSWindow *window;

- (IBAction)start:(id)sender;
- (IBAction)pause:(id)sender;
- (IBAction)stop:(id)sender;
@property (strong) IBOutlet NSTextField *label;

@property (strong)NSDate *startDate;
@property (strong)NSTimer *timer;

@property (assign)BOOL isRunning;
@property (assign)BOOL isPaused;

@property(assign)NSInteger secondsSinceStart;

@property(assign)NSInteger secondsPaused;
@end

在.m

#import "AppDelegate.h"

@implementation AppDelegate

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    self.label.stringValue=@"00:00:00";
    self.isRunning=NO;
    self.isPaused=NO;
    self.secondsPaused=0;
}

-(void)timerDisplay{

    if (self.isPaused) {
        self.secondsPaused++;
        return;
    }

    self.secondsSinceStart+=1;

    NSInteger seconds = self.secondsSinceStart % 60;
    NSInteger minutes = (self.secondsSinceStart / 60) % 60;
    NSInteger hours = self.secondsSinceStart / (60 * 60);
    NSString *result = nil;


    if (self.isRunning && !self.isPaused) {
        result = [NSString stringWithFormat:@"%02ld:%02ld:%02ld", hours, minutes, seconds];
        self.label.stringValue=result;
    }
}


- (IBAction)start:(id)sender {
    self.isRunning=!self.isRunning;
    self.isPaused=NO;
    self.secondsSinceStart=0;
    self.label.stringValue=@"00:00:00";


    self.startDate =[NSDate date];
    if (!self.timer) {
        self.timer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerDisplay) userInfo:nil repeats:YES];
    }
}

- (IBAction)pause:(id)sender {
    self.isPaused=!self.isPaused;
    NSLog(@"pause : %d",self.isPaused);
}

- (IBAction)stop:(id)sender {
    self.isRunning=NO;
    NSLog(@"start : %@",self.startDate);
    NSLog(@"end : %@",[NSDate date]);
    NSLog(@"paused : %ld",self.secondsPaused);

    NSInteger totalTime=self.secondsSinceStart+self.secondsPaused;

    NSInteger seconds = totalTime % 60;
    NSInteger minutes = (totalTime / 60) % 60;
    NSInteger hours = totalTime / (60 * 60);
    NSString *result = result = [NSString stringWithFormat:@"%02ld:%02ld:%02ld", hours, minutes, seconds];
    NSLog(@"Total : %@",result);

}
@end

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