iOS倒计时的实现方法

#import "ViewController.h"
#import "Timer.h"

@interface ViewController ()<TimerDelegate>

@property (nonatomic, strong) UIButton *button;
@property (nonatomic, strong) Timer *timer;

@end

@implementation ViewController

- (void)viewDidLoad {
 
 [super viewDidLoad];
 
 // 倒计时界面
 self.timer   = [[Timer alloc] initWithFrame:CGRectMake(10, 100, 200, 30)];
 self.timer.delegate = self; // 记得遵守代理
 self.timer.sceonds = 5;
 self.timer.layer.borderWidth = 1;
 self.timer.layer.cornerRadius = 5;
 self.timer.layer.borderColor = [UIColor orangeColor].CGColor;
 self.timer.label.font   = [UIFont systemFontOfSize:14];
 self.timer.label.textColor = [UIColor orangeColor];
 [self.view addSubview:self.timer];
 
 self.button     = [[UIButton alloc] initWithFrame:CGRectMake(10, 150, 100, 40)];
 self.button.layer.borderWidth = 1.0f;
 self.button.layer.borderColor = [UIColor blackColor].CGColor;
 [self.button setTitle:@"点击" forState:UIControlStateNormal];
 [self.button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
 [self.button setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];
 [self.button setTitleColor:[UIColor grayColor] forState:UIControlStateDisabled];
 [self.view addSubview:self.button];
 [self.button addTarget:self action:@selector(buttonEvent) forControlEvents:UIControlEventTouchUpInside];
}

- (void)buttonEvent {
 
 // 启动倒计时的方法，启动之后设置button点击失效
 [self.timer timerStart];
 self.button.enabled = NO;
 self.button.layer.borderColor = [UIColor grayColor].CGColor;
}

- (void)timerFinished:(Timer *)timer {

 // 计时完成之后，button恢复点击
 self.button.enabled = YES;
 self.button.layer.borderColor = [UIColor blackColor].CGColor;
}

@end