计时器&时钟

//计时器

{

//定义全局变量

//显示时间

UILabel *_timerLabel;

//开始计时和暂停的按钮

UIButton*_startButton;

//复位按钮

UIButton *_clearButton;

//计时的定时器

NSTimer *_timer;

//定义全局变量

int _second ;

int _minute ;

int _hour ;

}

---

- (void)viewDidLoad {

[super viewDidLoad];

_timerLabel= [[UILabel alloc] initWithFrame:CGRectMake(0, 100, 320, 50)];

_timerLabel.textAlignment=NSTextAlignmentCenter;

//枚举类型可以用等号=数字

// _timerLabel.textAlignment = 1;

_timerLabel.font= [UIFont systemFontOfSize:30];

_timerLabel.text=@"00:00:00";

[self.view addSubview:_timerLabel];

_startButton= [[UIButton alloc] initWithFrame:CGRectMake(200, 200, 60, 60)];

_startButton.backgroundColor= [UIColor grayColor];

[_startButton setTitle:@"开始" forState:UIControlStateNormal];

[_startButton setTitle:@"暂停" forState:UIControlStateSelected];

//圆形图案

_startButton.layer.cornerRadius= 30;

//剪切边界,imageview需要配置上一句使用，超出父视图部分不显示

// _startButton.clipsToBounds = YES;

[_startButton addTarget:self action:@selector(starBtnClick) forControlEvents:UIControlEventTouchUpInside];

[self.viewa ddSubview:_startButton];

_clearButton= [[UIButton alloc] initWithFrame:CGRectMake(60, 200, 60, 60)];

_clearButton.backgroundColor= [UIColor grayColor];

[_clearButton setTitle:@"复位" forState:UIControlStateNormal];

//圆形图案

_clearButton.layer.cornerRadius= 30;

// _startButton.clipsToBounds = YES;

[_clearButton addTarget:self action:@selector(clearButClick) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:_clearButton];

}

//开始计时

-(void)starBtnClick {

//让选中状态取反变换按钮的标题

_startButton.selected = !_startButton.selected;

//判断当前状态

//当前状态_startButton.selected == YES可以省略

//   !_startButton.selected表示==NO

if(!_startButton.selected) {

//如果当前不是选中状态,对应的标题是开始

//关闭(销毁)定时器

[_timer invalidate];

//销毁定时器之后,_timer指针指向的内容没有对象,变成野指针,容易造成程序崩溃,所以把指针写为nil

//销毁路径防止指向错误

_timer = nil;

} else {

//如果当前是选中状态,对应的标题是暂停

//创建一个定时器控制时间的改变

_timer= [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:@selector(timerChange) userInfo:nil repeats:YES];

}

}

//清空,复位

- (void)clearButClick {

//暂停状态中复位,显示开始

//把label时间归0

_hour= 0;

_minute= 0;

_second= 0;

_timerLabel.text=@"00:00:00";

//显示暂停,计时状态中复位,

//判断是否正在计时,如果按钮状态是选中状态,表示正在计时

if(_startButton.selected) {

//销毁定时器

[_timer invalidate];

_timer = nil;

//改变开始按钮状态

_startButton.selected=NO;

}

}

//更新时间的方法

- (void)timerChange {

//    //定义静态变量

//    static int second = 0;

//    static int minute = 0;

//    static int hour = 0;

//秒加1

_second++;

NSLog(@"%d",_second);

//如果到60秒,分钟加1,秒归0

if(_second == 60) {

_minute++;

_second= 0;

}

//如果到60分,时加1,分归0

if(_minute == 60) {

_hour++;

_minute= 0;

}

//把属性转换为字符串

NSString *string = [NSString stringWithFormat:@"%.2d:%.2d:%.2d",_hour,_minute,_second];

//更新label的显示内容

_timerLabel.text= string;

}

---

//时钟

- (BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions {

self.window= [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

// Override point for customization after application launch.

hourLabel= [[UILabel alloc] initWithFrame:CGRectMake(10, 100, 100, 30)];

hourLabel.text=@"00";

hourLabel.backgroundColor= [UIColor yellowColor];

hourLabel.textAlignment=NSTextAlignmentCenter;

[self.window addSubview:hourLabel];

minuteLabel= [[UILabel alloc] initWithFrame:CGRectMake(110, 100, 100, 30)];

minuteLabel.text=@"00";

minuteLabel.backgroundColor= [UIColor yellowColor];

minuteLabel.textAlignment=NSTextAlignmentCenter;

[self.window addSubview:minuteLabel];

secondLabel= [[UILabel alloc] initWithFrame:CGRectMake(210, 100, 100, 30)];

secondLabel.text=@"00";

secondLabel.backgroundColor= [UIColoryellowColor];

secondLabel.textAlignment=NSTextAlignmentCenter;

[self.window addSubview:secondLabel];

timer= [NSTimer scheduledTimerWithTimeInterval:1.0 target:selfselector:@selector(timeCount) userInfo:nil repeats:YES];

//    [timer fire];

_window.rootViewController= [[UIViewController alloc] init];

self.window.backgroundColor= [UIColor whiteColor];

[self.window makeKeyAndVisible];

return YES;

}

- (void)timeCount {

count++;

//  /取商 。%取余

//   130 / 60 = 2;

//   130 % 60 = 10;

int second = count% 60;//(0 - 59)取秒

NSString *secondStr;

if(second < 10) {

secondStr = [NSString stringWithFormat:@"0%d",second];

}else{

secondStr = [NSString stringWithFormat:@"%d",second];

}

secondLabel.text= secondStr;

//假设count == 3600

int minute  = count/ 60 % 60;

NSString *minuteStr;

if(minute < 10) {

minuteStr = [NSString stringWithFormat:@"0%d",minute];

}else{

minuteStr = [NSString stringWithFormat:@"%d",minute];

}

minuteLabel.text= minuteStr;

int hour =count/ 3600 % 24;

NSString *hourStr;

if(hour < 10) {

hourStr = [NSString stringWithFormat:@"0%d",hour];

}else{

hourStr = [NSString stringWithFormat:@"%d",hour];

}

hourLabel.text= hourStr;

}