定时器发送验证码

__block int timeout= 59;

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

dispatch_source_t _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);

dispatch_source_set_timer(_timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒执行

dispatch_source_set_event_handler(_timer, ^{

if(timeout<=0){

dispatch_source_cancel(_timer);

dispatch_async(dispatch_get_main_queue(), ^{

//sendtest为按钮

[sendtest setTitle:@"重新获取" forState:UIControlStateNormal];

[sendtest setTitleColor:BC_MASSTONEATTUNE_COLOR forState:UIControlStateNormal];

sendtest.userInteractionEnabled = YES;

});

}else{

int seconds = timeout % 60;

NSString *strTime = [NSString stringWithFormat:@"%.2d重新获取",seconds];

dispatch_async(dispatch_get_main_queue(), ^{

//sendtest为按钮

[sendtest setTitle:strTime forState:UIControlStateNormal];

[sendtest setTitleColor:BC_TEXTFIELDINPUT_COLOR forState:UIControlStateNormal];

sendtest.userInteractionEnabled = NO;

});

timeout--;

}

});

dispatch_resume(_timer);