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1 @interface MyPlanarCodeViewController () 2 //定义计时器 3 @property (nonatomic, strong) NSTimer *timer; 4 @end 5 6 @implementation MyPlanarCodeViewController 7 -(ApiGetCodeExcutor *)apiGetCodeExcutor{ 8 if (_apiGetCodeExcutor == nil) { 9 _apiGetCodeExcutor = [ApiGetCodeExcutor excutor]; 10 } 11 return _apiGetCodeExcutor; 12 } 13 - (void)viewDidLoad { 14 [super viewDidLoad]; 15 //启动计时器 16 [self startTimer]; 17 } 18 - (void)startTimer { 19 //60秒调用一次timerRepeat:方法 20 _timer = [NSTimer scheduledTimerWithTimeInterval:60 target:self selector:@selector(timerRepeat:) userInfo:nil repeats:YES]; 21 [[NSRunLoop currentRunLoop] addTimer:_timer forMode:NSDefaultRunLoopMode]; 22 [_timer fire]; 23 } 24 //重复进行的操作放到这里 25 -(void)timerRepeat:(NSTimer *)timer { 26 ApiRequestStateHandler * apiRequest = [ApiRequestStateHandler apiRequestStateHandlerOnSuccess:^(ApiExcutor *apiExcutor, BOOL *cache) { 27 if(self.apiGetCodeExcutor.status == 1){ 28 [self.codeImageView sd_setImageWithURL:[NSURL URLWithString:self.apiGetCodeExcutor.imageURL] placeholderImage:nil completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) { 29 [self hideHud]; 30 [[SDImageCache sharedImageCache] removeImageForKey:self.apiGetCodeExcutor.imageURL]; 31 }]; 32 self.codeImageView.userInteractionEnabled = NO; 33 }else{ 34 [self hideHud]; 35 [self showAlertViewWithTitle:@"请等待老师开启签到后点击二维码区域重新获取"]; 36 } 37 } onFail:^(ApiExcutor *apiExcutor, NSError *error) { 38 // 39 [self hideHud]; 40 [self showHint:@"网络通讯异常"]; 41 }]; 42 [self.apiGetCodeExcutor getQRCodeWithUserid:[CUserManager sharedManager].user.userid withCourseId:self.course.sjddid type:self.type withDeviceIdentifier:device withApiRequestStateHandler:apiRequest]; 43 } 44 //销毁计时器。避免计时器一直在运行状态 45 - (void)viewDidDisappear:(BOOL)animated { 46 [_timer invalidate]; 47 _timer = nil ; 48 } 49 //- (void)dealloc { 50 // [_timer invalidate]; 51 // _timer = nil; 52 //} 53 @end