iOS 时间

1.获取系统当前时间

NSDate * senddate=[NSDate date];

NSDateFormatter *dateformatter=[[NSDateFormatter alloc] init];

[dateformatter setDateFormat:@"YYYY-MM-dd HH:mm:ss"];

NSString * str=[dateformatter stringFromDate:senddate];

2.获取当前系统时间的秒数

NSTimeInterval time = [[NSDate date] timeIntervalSince1970];

long long int date = (long long int)time;

3.以秒数来获取的时间

NSDate * d=[NSDate dateWithTimeIntervalSince1970:date];

NSDateFormatter * dateformatter=[[NSDateFormatter alloc] init];

[dateformatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

NSString * s=[dateformatter stringFromDate:d];

4.获取星期日期

NSArray * arrWeek=[NSArray arrayWithObjects:@"星期日",@"星期一",@"星期二",@"星期三",@"星期四",@"星期五",@"星期六", nil];

NSDate *date = [NSDate date];

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];

NSDateComponents *comps = [[NSDateComponents alloc] init];

NSInteger unitFlags = NSCalendarUnitYear |

NSCalendarUnitMonth |

NSCalendarUnitDay |

NSCalendarUnitWeekday |

NSCalendarUnitHour |

NSCalendarUnitMinute |

NSCalendarUnitSecond;

comps = [calendar components:unitFlags fromDate:date];

int week = (int)[comps weekday];

int year=(int)[comps year];

int month = (int)[comps month];

int day = (int)[comps day];

NSLog(@"date==%@",[NSString stringWithFormat:@"%d年%d月%d日%@",year,month,day,[arrWeek objectAtIndex:week-1]]);