-(void)startTime{
__block int timeout=60; //倒计时时间
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){ //倒计时结束，关闭
dispatch_source_cancel(_timer);
dispatch_async(dispatch_get_main_queue(), ^{
//设置界面的按钮显示 根据自己需求设置 特别注明：UI的改变一定要在主线程中进行
//倒计时完成,恢复到原来的效果
_timeLabel.text = @"获取验证码";
_sendCode.userInteractionEnabled=YES;
});
}else{
int seconds = timeout % 60;
if(seconds == 0&&timeout==60){
seconds = 60;
}
NSString *strTime = [NSString stringWithFormat:@"%.2dS", seconds];
dispatch_async(dispatch_get_main_queue(), ^{
//设置界面的按钮显示 根据自己需求设置
// NSLog(@"____%@",strTime);
_timeLabel.text = strTime;//倒计时时间显示
_sendCode.userInteractionEnabled=NO;//倒计时时禁止用户再次点击按钮倒计时
});
timeout--;
}
});
dispatch_resume(_timer);
}
