我有以下字符串：
“2011-08-31 14:12:24”
如果已经过去了多少时间，我该如何格式化它以使其显示为“2 小时前”？
我有一些类似的代码，但不完全是：
+(NSString*)toShortTimeIntervalString:(NSString*)sDate
{
NSDateFormatter* df = [[NSDateFormatter alloc]init];
[df setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZ"];
NSDate* date = [df dateFromString:[sDate stringByReplacingOccurrencesOfString:@"Z" withString:@"-0000"]];
[df release];
NSDate* today = [[NSDate alloc] init];
NSDate *d = date; //[_twitter_dateFormatter dateFromString:sDate];
NSTimeInterval interval = [today timeIntervalSinceDate:d];
[today release];
//TODO: added ABS wrapper
double res = 0;
NSString* result;
if(interval > SECONDS_IN_WEEK)
{
res = fabs(interval / SECONDS_IN_WEEK);
result = [NSString stringWithFormat:@"%1.0fw ago", res];
}
else if(interval > SECONDS_IN_DAY)
{
res = fabs(interval / SECONDS_IN_DAY);
result = [NSString stringWithFormat:@"%1.0fd ago", res];
}
else if (interval > SECONDS_IN_HOUR){
res = fabs(interval / SECONDS_IN_HOUR);
result = [NSString stringWithFormat:@"%1.0fh ago", res];
}
else if (interval > SECONDS_IN_MIN) {
res = fabs(interval / SECONDS_IN_MIN);
result = [NSString stringWithFormat:@"%1.0fm ago", res];
}
else
{
interval = fabs(interval);
result = [NSString stringWithFormat:@"%1.0fs ago", interval];
}
return result;
}