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]]);