計算一個時間距離現在的時間過了多長的時間，單位為天，小時、分鐘、秒數
以天為單位計算
// 計算相差了幾天
- (int)intervalSinceNow: (NSString *) theDate
{
NSDateFormatter *date=[[NSDateFormatter alloc] init];
[date setDateFormat:@"yyyy-MM-dd HH:mm zzz"];
NSDate *d=[date dateFromString:theDate];
NSTimeInterval late=[d timeIntervalSince1970]*1;
NSDate* dat = [NSDate dateWithTimeIntervalSinceNow:0];
NSTimeZone *zone = [NSTimeZone systemTimeZone];
NSInteger interval = [zone secondsFromGMTForDate: dat];
NSDate *localDate = [dat? dateByAddingTimeInterval:interval];
NSTimeInterval now=[localDate timeIntervalSince1970]*1;
NSString *timeString=@"";
NSTimeInterval cha=now-late;
if (cha/86400>1)
{
timeString = [NSString stringWithFormat:@"%f", cha/86400];
timeString = [timeString substringToIndex:timeString.length-7];
return [timeString intValue];
}
return -1;
}
時間和字符串互換轉換：
+ (NSString *)stringFromDate:(NSDate *)date{
NSTimeZone *zone = [NSTimeZone systemTimeZone];
NSInteger interval = [zone secondsFromGMTForDate: date];
NSDate *localDate = [date? dateByAddingTimeInterval:interval];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
//zzz表示時區，zzz可以刪除，這樣返回的日期字符將不包含時區信息。
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm zzz"];
//? ? [dateFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"zh_CN"]];
NSString *destDateString = [dateFormatter stringFromDate:localDate];
return destDateString;
}；
為了避免其中時間區域造成的誤差范圍盡可能的縮小采用一個時區類別記錄
NSTimeZone *zone = [NSTimeZone systemTimeZone];
NSInteger interval = [zone secondsFromGMTForDate: date];
NSDate *localDate = [date? dateByAddingTimeInterval:interval];
每次處理的Date都是時區格式化之后的時間，以便于計算誤差減小。
兩個時間之差
- (NSString *)intervalFromLastDate: (NSString *) dateString1? toTheDate:(NSString *) dateString2
{
NSArray *timeArray1=[dateString1 componentsSeparatedByString:@"."];
dateString1=[timeArray1 objectAtIndex:0];
NSArray *timeArray2=[dateString2 componentsSeparatedByString:@"."];
dateString2=[timeArray2 objectAtIndex:0];
NSLog(@"%@.....%@",dateString1,dateString2);
NSDateFormatter *date=[[NSDateFormatter alloc] init];
[date setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *d1=[date dateFromString:dateString1];
NSTimeInterval late1=[d1 timeIntervalSince1970]*1;
NSDate *d2=[date dateFromString:dateString2];
NSTimeInterval late2=[d2 timeIntervalSince1970]*1;
NSTimeInterval cha=late2-late1;
NSString *timeString=@"";
NSString *house=@"";
NSString *min=@"";
NSString *sen=@"";
sen = [NSString stringWithFormat:@"%d", (int)cha%60];
//? ? ? ? min = [min substringToIndex:min.length-7];
//? ? 秒
sen=[NSString stringWithFormat:@"%@", sen];
min = [NSString stringWithFormat:@"%d", (int)cha/60%60];
//? ? ? ? min = [min substringToIndex:min.length-7];
//? ? 分
min=[NSString stringWithFormat:@"%@", min];
//? ? 小時
house = [NSString stringWithFormat:@"%d", (int)cha/3600];
//? ? ? ? house = [house substringToIndex:house.length-7];
house=[NSString stringWithFormat:@"%@", house];
timeString=[NSString stringWithFormat:@"%@:%@:%@",house,min,sen];
return timeString;
}
一個時間距現在的時間
- (NSString *)intervalSinceNow: (NSString *) theDate
{
NSArray *timeArray=[theDate componentsSeparatedByString:@"."];
theDate=[timeArray objectAtIndex:0];
NSDateFormatter *date=[[NSDateFormatter alloc] init];
[date setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *d=[date dateFromString:theDate];
NSTimeInterval late=[d timeIntervalSince1970]*1;
NSDate* dat = [NSDate date];
NSTimeInterval now=[dat timeIntervalSince1970]*1;
NSString *timeString=@"";
NSTimeInterval cha=late-now;
if (cha/3600<1) { // 分鐘
timeString = [NSString stringWithFormat:@"%f", cha/60];
timeString = [timeString substringToIndex:timeString.length-7];
timeString=[NSString stringWithFormat:@"剩余%@分", timeString];
}
if (cha/3600>1&&cha/86400<1) { ?// 小時
timeString = [NSString stringWithFormat:@"%f", cha/3600];
timeString = [timeString substringToIndex:timeString.length-7];
timeString=[NSString stringWithFormat:@"剩余%@小時", timeString];
}
if (cha/86400>1) // 天
{
timeString = [NSString stringWithFormat:@"%f", cha/86400];
timeString = [timeString substringToIndex:timeString.length-7];
timeString=[NSString stringWithFormat:@"剩余%@天", timeString];
}
return timeString;
}
