@interface IDCountDownButton : UIButton
/** 驗(yàn)證碼倒計(jì)時(shí)的時(shí)長(zhǎng) */
@property (nonatomic, assign) NSInteger durationOfCountDown;
@end

@interface IDCountDownButton ()
/** 保存倒計(jì)時(shí)按鈕的非倒計(jì)時(shí)狀態(tài)的title */
@property (nonatomic, copy) NSString *originalTitle;
/** 保存倒計(jì)時(shí)的時(shí)長(zhǎng) */
@property (nonatomic, assign) NSInteger tempDurationOfCountDown;
/** 定時(shí)器對(duì)象 */
@property (nonatomic, strong) NSTimer *countDownTimer;
@end

- (void)setTitle:(NSString *)title forState:(UIControlState)state {
 [super setTitle:title forState:state];
 // 倒計(jì)時(shí)過程中title的改變不更新originalTitle
 if (self.tempDurationOfCountDown == self.durationOfCountDown) {
 self.originalTitle = title;
 }
}

- (void)setDurationOfCountDown:(NSInteger)durationOfCountDown {
 _durationOfCountDown = durationOfCountDown;
 self.tempDurationOfCountDown = _durationOfCountDown;
}

- (instancetype)initWithFrame:(CGRect)frame {
 if (self = [super initWithFrame:frame]) {
 // 設(shè)置默認(rèn)的倒計(jì)時(shí)時(shí)長(zhǎng)為60秒
 self.durationOfCountDown = 60;
 // 設(shè)置button的默認(rèn)標(biāo)題為“獲取驗(yàn)證碼”
 [self setTitle:@"獲取驗(yàn)證碼" forState:UIControlStateNormal];
 }
 return self;
}
- (instancetype)initWithCoder:(NSCoder *)aDecoder {
 if (self = [super initWithCoder:aDecoder]) {
 // 設(shè)置默認(rèn)的倒計(jì)時(shí)時(shí)長(zhǎng)為60秒
 self.durationOfCountDown = 60;
 // 設(shè)置button的默認(rèn)標(biāo)題為“獲取驗(yàn)證碼”
 [self setTitle:@"獲取驗(yàn)證碼" forState:UIControlStateNormal];
 }
 return self;
}

- (BOOL)beginTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event {
 // 若正在倒計(jì)時(shí)，不響應(yīng)點(diǎn)擊事件
 if (self.tempDurationOfCountDown != self.durationOfCountDown) {
 return NO;
 }
 // 若未開始倒計(jì)時(shí)，響應(yīng)并傳遞點(diǎn)擊事件，開始倒計(jì)時(shí)
 [self startCountDown];
 return [super beginTrackingWithTouch:touch withEvent:event];
}

- (void)startCountDown {
 // 創(chuàng)建定時(shí)器
 self.countDownTimer = [NSTimer timerWithTimeInterval:1 target:self selector:@selector(updateIDCountDownButtonTitle) userInfo:nil repeats:YES];
 // 將定時(shí)器添加到當(dāng)前的RunLoop中（自動(dòng)開啟定時(shí)器）
 [[NSRunLoop currentRunLoop] addTimer:self.countDownTimer forMode:NSRunLoopCommonModes];
}

- (void)updateIDCountDownButtonTitle {
 if (self.tempDurationOfCountDown == 0) {
 // 設(shè)置IDCountDownButton的title為開始倒計(jì)時(shí)前的title
 [self setTitle:self.originalTitle forState:UIControlStateNormal];
 // 恢復(fù)IDCountDownButton開始倒計(jì)時(shí)的能力
 self.tempDurationOfCountDown = self.durationOfCountDown;
 [self.countDownTimer invalidate];
 } else {
 // 設(shè)置IDCountDownButton的title為當(dāng)前倒計(jì)時(shí)剩余的時(shí)間
 [self setTitle:[NSString stringWithFormat:@"%zd秒", self.tempDurationOfCountDown--] forState:UIControlStateNormal];
 }
}

- (void)dealloc {
 [self.countDownTimer invalidate];
}

@interface ViewController ()
/** 驗(yàn)證碼倒計(jì)時(shí)的button */
@property (nonatomic, strong) IDCountDownButton *vertificationCodeIDCountDownButton;
@end

- (void)viewDidLoad {
 [super viewDidLoad];
 // 創(chuàng)建vertificationCodeIDCountDownButton
 self.vertificationCodeIDCountDownButton = [[IDCountDownButton alloc] initWithFrame:CGRectMake(160, 204, 120, 44)];
 // 添加點(diǎn)擊事件
 [self.vertificationCodeIDCountDownButton addTarget:self action:@selector(vertificationCodeIDCountDownButtonClick:) forControlEvents:UIControlEventTouchUpInside];
 // 設(shè)置標(biāo)題相關(guān)屬性
 [self.vertificationCodeIDCountDownButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
 [self.vertificationCodeIDCountDownButton setTitle:@"獲取驗(yàn)證碼" forState:UIControlStateNormal];
 // 設(shè)置背景圖片
 [self.vertificationCodeIDCountDownButton setBackgroundImage:[UIImage imageNamed:@"redButton"] forState:UIControlStateNormal];
 // 設(shè)置倒計(jì)時(shí)時(shí)長(zhǎng)
 self.vertificationCodeIDCountDownButton.durationOfCountDown = 10;
 // 將vertificationCodeIDCountDownButton添加的控制器的view中
 [self.view addSubview:self.vertificationCodeIDCountDownButton];
}

- (void)vertificationCodeIDCountDownButtonClick:(UIButton *)button {
 // TODO：調(diào)用服務(wù)器接口，獲取驗(yàn)證碼
}