NSTimer 使用

phone爲我們提供了一個很強大得時間定時器 NSTimer
他可以完成任何定時功能：
我們使用起來也很簡單，只要記住三要素就可以，具體得三要素是：時間間隔NSTimeInterval浮點型，事件代理
delegate和事件處理方法@selector（）；就可以用
+ (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)ti target:(id)aTarget selector:(SEL)aSelector userInfo:(id)userInfo repeats:(BOOL)yesOrNo; 來初始化一個 時間定時器

NSTimer是Cocoa中比較常用的定時器類，基本操作如下：
handleTimer方法可以自行定義。在需要的地方創建timer即可，handleTimer就可以每0.5秒執行一次。

例：

 

- (void) handleTimer: (NSTimer *) timer
{
   //在這裏進行處理
}
 
NSTimer *timer;
 
timer = [NSTimer scheduledTimerWithTimeInterval: 0.5
             target: self
             selector: @selector(handleTimer:)
             userInfo: nil
             repeats: YES];

 

 

下面我寫了一個很簡單得例子
-(void)initTimer
{
//時間間隔
NSTimeInterval timeInterval =1.0 ;
//定時器
NSTimer   showTimer = [NSTimer scheduledTimerWithTimeInterval:maxShowTime
                                                                 target:self
                                                            selector:@selector(handleMaxShowTimer:)
                                                               userInfo:nil
                                                                repeats:NO];
}
//觸發事件
- (void)handleMaxShowTimer:(NSTimer *)theTimer
{
       NSDateFormatter dateFormator = [[NSDateFormatter alloc] init];
       dateFormator.dateFormat = @"yyyy-MM-dd  HH:mm:ss";
       NSString *date = [dateformater stringFromDate:[NSDate date]];
        if([date isEqualToString:@"2010-11-09 23:59:59"])
          {
                UIAlertView *alert = [[UIAlertView alloc] initWithTitle:TITLE_NAME
                                                    message:@"現在馬上就有新的一天了！"
                                                   delegate:self
                                          cancelButtonTitle:nil
                                          otherButtonTitles:CONFIRM_TITLE, nil];
                [alert show];
                [alert release];
          }
      [data release];
      [dateFormator release];
}
另外附一個例子：方框賽跑

      - (void)viewDidLoad

        {

                         [super viewDidLoad];

                CGRect workingFrame;

                workingFrame.origin.x = 15;

                workingFrame.origin.y = 400;

                workingFrame.size.width = 40;

                workingFrame.size.height = 40;

               

                for(int i = 0; i < 6; i++)

                {

                        UIView *myView = [[UIView alloc] initWithFrame:workingFrame];

                        [myView setTag:i];//標記方塊

                        [myView setBackgroundColor:[UIColor blueColor]];

                       

                        workingFrame.origin.x = workingFrame.origin.x + workingFrame.size.width + 10;

                        [self.view addSubview:myView];

                }