目录：
1、时区转换
2、日期格式转换
3、时间格式转换
4、计算今天开始7天内日期、星期（今天，01-13|星期六，01-14|...共7天，使用方法5、6、7、8）
5、日期转换成字符串
6、字符串转换成日期
7、获取当月的天数
8、获取指定的日期是星期几
9、获取指定日期的年，月，日，星期，时,分,秒信息
1.时区转换（国际时间转换成本地时区时间）
//转换时区 输入时间 输出＋8时间
+(NSDate *)convertDateToLocalTime:(NSDate *)forDate
{
NSTimeZone *nowTimeZone = [NSTimeZone localTimeZone];
int timeOffset = [nowTimeZone secondsFromGMTForDate:forDate];
NSDate *newDate = [forDate dateByAddingTimeInterval:timeOffset];
return newDate;
}
2.日期格式转换（把20020912变成2002-09-12）
+ (NSString *)dateFormat:(NSString *)sourceString
{
if ([sourceString length] < 8)
{
return @"";
}
NSString *timeString = sourceString;
NSRange yearRange = NSMakeRange(0, 4);
NSString *yearString = [timeString substringWithRange:yearRange];
NSRange monthRange = NSMakeRange(4, 2);
NSString *monthString = [timeString substringWithRange:monthRange];
NSRange dayRange = NSMakeRange(6, 2);
NSString *dayString = [timeString substringWithRange:dayRange];
return [NSString stringWithFormat:@"%@-%@-%@",yearString,monthString,dayString];
}
3、时间格式转换（把160718变成16:07:18）
+ (NSString *)timeFormat:(NSString *)sourceString
{
if ([sourceString length] < 6)
{
return sourceString;
}
NSString *timeString = sourceString;
NSRange hourRange = NSMakeRange(0, 2);
NSString *hourString = [timeString substringWithRange:hourRange];
NSRange minuteRange = NSMakeRange(2, 2);
NSString *minuteString = [timeString substringWithRange:minuteRange];
NSRange secondRange = NSMakeRange(4, 2);
NSString *secondString = [timeString substringWithRange:secondRange];
return [NSString stringWithFormat:@"%@:%@:%@",hourString,minuteString,secondString];
}
4.计算7天内日期、星期，并按格式返回
//自定义方法
- (void)showDateViewWithMaxCount:(NSInteger)maxCount block:(void (^)(NSArray *))callBack
{
//日历初始化
self.myCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSMutableArray *dateMtbArr = [NSMutableArray array];
NSDate *currentDate = [NSDate date];
// __今天____01-05
NSString *curDateStr = [self dateToStringWithDate:currentDate];
NSString *curMdStr = [[self dateToStringWithDate:currentDate] substringFromIndex:5];
curMdStr = [curMdStr stringByReplacingOccurrencesOfString:@"/" withString:@"-"];
NSString *curStr = [NSString stringWithFormat:@" 今天 %@",curMdStr];
[dateMtbArr addObject:@{@"showStr":curStr,
@"dateStr":curDateStr}];
//计算本月天数是否够用
NSInteger daysInMonth = [self getNumberOfDaysInMonthWithDate:currentDate];
//本月要取天数
NSInteger thisMonthDays = daysInMonth - [curDateStr substringFromIndex:7].integerValue;
thisMonthDays = thisMonthDays >= maxCount - 1 ? maxCount - 1 : thisMonthDays;
for (int i = 0 ; i < thisMonthDays; i ++)
{
//构造下一天字符串（_01-05__星期日）
NSTimeInterval oneDay = 24 * 60 * 60;
NSDate *nextDate = [NSDate dateWithTimeIntervalSinceNow:oneDay * (i + 1)];
NSString *dateStr = [self dateToStringWithDate:nextDate];
NSString *mdStr = [dateStr substringFromIndex:5];// 01/05
mdStr = [mdStr stringByReplacingOccurrencesOfString:@"/" withString:@"-"];// 01-05
NSString *weekStr = [self getweekDayWithDate:nextDate];// 星期日
NSString *nextStr = [NSString stringWithFormat:@"%@ %@",weekStr,mdStr];
[dateMtbArr addObject:@{@"showStr":nextStr,
@"dateStr":dateStr}];
}
//下月要取天数
if (thisMonthDays != maxCount - 1)
{
NSInteger nextMonthDays = maxCount - 1 - thisMonthDays;
NSString *curYear = [curDateStr substringToIndex:4];
NSString *curMonth = [curDateStr substringWithRange:NSMakeRange(5, 2)];
NSString *nextYear = @"";
NSString *nextMonth = @"";
if (curMonth.integerValue == 12)
{
nextMonth = @"01";//改成01月 年+1
nextYear = [NSString stringWithFormat:@"%d",curYear.intValue + 1];
}
else
{
nextMonth = [NSString stringWithFormat:@"%d",curMonth.intValue + 1];
nextYear = curYear;
}
for (int i = 0; i < nextMonthDays; i ++)
{
NSString *dateStr = [NSString stringWithFormat:@"%@/%@/%d",nextYear,nextMonth,i + 1];
NSDate *nextDate = [self stringToDateWithString:dateStr];
NSString *mdStr = [dateStr substringFromIndex:5];// 01/05
mdStr = [mdStr stringByReplacingOccurrencesOfString:@"/" withString:@"-"];// 01-05
NSString *weekStr = [self getweekDayWithDate:nextDate];// 星期日
NSString *nextStr = [NSString stringWithFormat:@"%@ %@",weekStr,mdStr];
[dateMtbArr addObject:@{@"showStr":nextStr,
@"dateStr":dateStr}];
}
}
callBack([NSArray arrayWithArray:dateMtbArr]);
}
5、日期转换成字符串
- (NSString *)dateToStringWithDate:(NSDate *)date
{
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy/MM/dd"]; //只获取年月日的数据
return [formatter stringFromDate:date];
}
6、 字符串转换成日期
- (NSDate *)stringToDateWithString:(NSString *)string
{
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy/MM/dd"]; // 年/月/日
return [formatter dateFromString:string];
}
7、 获取当月的天数
- (NSInteger)getNumberOfDaysInMonthWithDate:(NSDate *)date
{
NSRange range = [self.myCalendar rangeOfUnit:NSDayCalendarUnit
inUnit: NSMonthCalendarUnit
forDate:date];
return range.length;
}
8.获取指定的日期是星期几
/**
获取指定的日期是星期几
@param date 日期
@return 星期几
*/
- (NSString *)getweekDayWithDate:(NSDate *)date
{
NSDateComponents *comps = [self.myCalendar components:NSWeekdayCalendarUnit fromDate:date];
NSString *dateStr;
// 1 是周日，2是周一 3.以此类推
switch ([comps weekday])
{
case 1:
dateStr = @"星期日";
break;
case 2:
dateStr = @"星期一";
break;
case 3:
dateStr = @"星期二";
break;
case 4:
dateStr = @"星期三";
break;
case 5:
dateStr = @"星期四";
break;
case 6:
dateStr = @"星期五";
break;
case 7:
dateStr = @"星期六";
break;
default:
break;
}
return dateStr;
}
9、 获取指定日期的年，月，日，星期，时,分,秒信息
/**
* NSCalendarUnitWeekday
* 获取指定日期的年，月，日，星期，时,分,秒信息
*/
- (void) getDateInfo
{
NSDate * date = [NSDate date];
NSCalendar * calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; // 指定日历的算法 NSCalendarIdentifierGregorian,NSGregorianCalendar
// NSDateComponent 可以获得日期的详细信息，即日期的组成
NSDateComponents *comps = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit|NSHourCalendarUnit|NSMinuteCalendarUnit|NSSecondCalendarUnit|NSWeekCalendarUnit|NSWeekdayCalendarUnit fromDate:date];
NSLog(@"年 = year = %ld",comps.year);
NSLog(@"月 = month = %ld",comps.month);
NSLog(@"日 = day = %ld",comps.day);
NSLog(@"时 = hour = %ld",comps.hour);
NSLog(@"分 = minute = %ld",comps.minute);
NSLog(@"秒 = second = %ld",comps.second);
NSLog(@"星期 =weekDay = %ld ",comps.weekday);
}