iOS 获取当前月份一共多少天 ，获取当前某年某月某日, 当前日期星期几

  //1.获取当月的总天数

    NSCalendar *calendar = [NSCalendarcurrentCalendar];

    NSRange range = [calendarrangeOfUnit:NSDayCalendarUnitinUnit:NSMonthCalendarUnitforDate:[NSDatedate]];

    NSUInteger numberOfDaysInMonth = range.length;

    NSLog(@"%lu", (unsignedlong)numberOfDaysInMonth);

    

    //2.获取当前年份,月份,号数

    unsigned unitFlags =NSYearCalendarUnit |NSMonthCalendarUnit |NSDayCalendarUnit;

    NSDateComponents *components = [calendarcomponents:unitFlags fromDate:[NSDatedate]];

    NSLog(@"%ld, %ld, %ld", (long)components.year, (long)components.month, (long)components.day);

    

    

    //3.获取当前日期星期几

    NSArray *weekdays = [NSArrayarrayWithObjects:@"星期日",@"周一",@"周二",@"周三",@"周四",@"周五",@"周六",nil];

    NSTimeZone *timeZone = [[NSTimeZonealloc] initWithName:@"Asia/Shanghai"];

    [calendar setTimeZone: timeZone];

    NSDate *date = [NSDatedate];

    NSCalendarUnit calendarUnit =NSWeekdayCalendarUnit;

    NSDateComponents *theComponents = [calendarcomponents:calendarUnit fromDate:date];

    NSLog(@"%@", [weekdaysobjectAtIndex:theComponents.weekday]);