IOS开发代码分享之用nstimer实现倒计时功能
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2023-12-28 20:58:16
用nstimer实现倒计时功能,废话不多说,直接上代码,详细解释请参照注释
//
[nstimer scheduledtimerwithtimeinterva...
用nstimer实现倒计时功能,废话不多说,直接上代码,详细解释请参照注释
// [nstimer scheduledtimerwithtimeinterval:1.0 target:self selector:@selector(timerfiremethod:) userinfo:nil repeats:yes]; // - (void)timerfiremethod:(nstimer *)thetimer { bool timestart = yes; nscalendar *cal = [nscalendar currentcalendar];//定义一个nscalendar对象 nsdatecomponents *endtime = [[nsdatecomponents alloc] init]; //初始化目标时间... nsdate *today = [nsdate date]; //得到当前时间 nsdateformatter *dateformatter = [[nsdateformatter alloc] init]; [dateformatter setdateformat:@"yyyy-mm-dd hh:mm:ss"]; nsdate *datestring = [dateformatter datefromstring:todate]; nsstring *overdate = [dateformatter stringfromdate:datestring]; // nslog(@"overdate=%@",overdate); static int year; static int month; static int day; static int hour; static int minute; static int second; if(timestart) {//从nsdate中取出年月日,时分秒,但是只能取一次 year = [[overdate substringwithrange:nsmakerange(0, 4)] intvalue]; month = [[overdate substringwithrange:nsmakerange(5, 2)] intvalue]; day = [[overdate substringwithrange:nsmakerange(8, 2)] intvalue]; hour = [[overdate substringwithrange:nsmakerange(11, 2)] intvalue]; minute = [[overdate substringwithrange:nsmakerange(14, 2)] intvalue]; second = [[overdate substringwithrange:nsmakerange(17, 2)] intvalue]; timestart= no; } [endtime setyear:year]; [endtime setmonth:month]; [endtime setday:day]; [endtime sethour:hour]; [endtime setminute:minute]; [endtime setsecond:second]; nsdate *overtime = [cal datefromcomponents:endtime]; //把目标时间装载入date //用来得到具体的时差,是为了统一成北京时间 unsigned int unitflags = nsyearcalendarunit| nsmonthcalendarunit| nsdaycalendarunit| nshourcalendarunit| nsminutecalendarunit| nssecondcalendarunit; nsdatecomponents *d = [cal components:unitflags fromdate:today todate:overtime options:0]; nsstring *t = [nsstring stringwithformat:@"%d", [d day]]; nsstring *h = [nsstring stringwithformat:@"%d", [d hour]]; nsstring *fen = [nsstring stringwithformat:@"%d", [d minute]]; if([d minute] < 10) { fen = [nsstring stringwithformat:@"0%d",[d minute]]; } nsstring *miao = [nsstring stringwithformat:@"%d", [d second]]; if([d second] < 10) { miao = [nsstring stringwithformat:@"0%d",[d second]]; } // nslog(@"===%@天 %@:%@:%@",t,h,fen,miao); [_longtime settext:[nsstring stringwithformat:@"%@天 %@:%@:%@",t,h,fen,miao]]; if([d second] > 0) { //计时尚未结束,do_something // [_longtime settext:[nsstring stringwithformat:@"%@:%@:%@",d,fen,miao]]; } else if([d second] == 0) { //计时结束 do_something } else{ //计时器失效 [thetimer invalidate]; } }