（5.20）时间戳记触发定时器控制计数

//  mainViewController.m
//  雪花
//
//  Created by pg
on 14-5-20.
//  Copyright (c) 2014年 mqd. All rights
reserved.
//

#import "mainViewController.h"

@interface
mainViewController ()
//游戏时钟
@property(strong,nonatomic)CADisplayLink
*gameTime;
//时钟戳记
@property(assign,nonatomic) CFTimeInterval
startTime;
@end

@implementation mainViewController

-
(void)viewDidLoad

{
    
    [super
viewDidLoad];
    //初始化时间撮箕
   
self.startTime = 0;
    //1,实例化游戏时钟
   
self.gameTime = [CADisplayLink displayLinkWithTarget:self
selector:@selector(updateTime:)];
   
//2，添加到主运行循环
    
    [self.gameTime
addToRunLoop:[NSRunLoop mainRunLoop]
forMode:NSDefaultRunLoopMode];
    
  
 
    
}
    
   
-(void)updateTime:(CADisplayLink *)sender{
  
 
        if (self.startTime == 0)
{
           
self.startTime = sender.timestamp;
       
}
      
 
        CFTimeInterval deleTime =
sender.timestamp - self.startTime;
       
if (deleTime > 1.0)
{
           
NSLog(@"触发了");
           
self.startTime = sender.timestamp;
       
}
        
   
}

@end