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