iOS 倒计时

//

//  RootViewController.m

//  MyTimerDemo

//

//  Created by huluo on 1/21/14.

//  Copyright (c) 2014 bluemobi.cn. All rights reserved.

//



#import "RootViewController.h"



@interface RootViewController ()



@end



@implementation RootViewController

{

    UITableView  *timerTableView;

    NSMutableArray  *timeArr;

    

    NSTimer  *myTimer;

    NSDate  *startDate;

    NSDate*  futureDate;

}



- (void)dealloc

{

    [timerTableView  release];

    [timeArr  release];

    [myTimer invalidate];

    [super dealloc];

}







- (void)viewDidLoad

{

    [super viewDidLoad];

    // Do any additional setup after loading the view.

    self.view.backgroundColor=[UIColor  brownColor];

    

    timeArr=[[NSMutableArray  alloc]initWithCapacity:0];

    for (int i=0; i<5; i++) {

        int random=arc4random()%10000+1;//1~10000

        NSTimeInterval deltTime = (NSTimeInterval)random;

        futureDate = [[NSDate date] dateByAddingTimeInterval:deltTime]; //未来时间

        [timeArr  addObject:futureDate];

    }



    timerTableView=[[UITableView  alloc]initWithFrame:CGRectMake(0, 0, 320, 480) style:UITableViewStylePlain];

    timerTableView.delegate=self;

    timerTableView.dataSource=self;

    [self.view  addSubview:timerTableView];



     myTimer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(refreshTime) userInfo:nil repeats:YES];

}







#pragma mark ----tableView----



-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView

{

    return 1;

}



-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

    return [timeArr count];

}



- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

{

    return 50.0f;

}



- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

   

    UITableViewCell* cell=(UITableViewCell  *)[tableView  dequeueReusableCellWithIdentifier:@"cell"];

    if(cell==nil)

    {

        cell=[[[UITableViewCell  alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cell"]autorelease];

        

      

    }

     NSDate  *toDate=[timeArr  objectAtIndex:indexPath.row];

     startDate = [NSDate date];

    long  leftSeconds=[toDate timeIntervalSinceDate:startDate];

    NSInteger seconds = leftSeconds % 60;

    NSInteger minutes = (leftSeconds / 60) % 60;

    NSInteger hours = leftSeconds / (60 * 60);

    if (hours==0) {

        cell.textLabel.text = [NSString stringWithFormat:@"%02d:%02d", minutes, seconds];

    }else{

    cell.textLabel.text = [NSString stringWithFormat:@"%02d:%02d:%02d", hours, minutes, seconds];

    }

    

    return cell;

}





//刷新时间

-(void)refreshTime

{

    startDate  = [ [ NSDate date];

    [timerTableView reloadData];

}