时间的显示转化

-  (NSString*)strDateDisplyForTime:(NSString*)strTime {
double dTime = [strTime doubleValue];
NSDate *d = [NSDate dateWithTimeIntervalSince1970:dTime];
NSDate *date = [NSDate date];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setTimeZone:[NSTimeZone localTimeZone]];
[dateFormatter setDateFormat:@"yyyy-MM-dd"];

NSString *str1 = [dateFormatter stringFromDate:d];
NSString *str2 = [dateFormatter stringFromDate:date];
[dateFormatter release];
if ([str1 isEqualToString:str2]) {
NSDateFormatter *dateFormatter2 = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter2 setTimeZone:[NSTimeZone localTimeZone]];
[dateFormatter2 setDateFormat:@"HH:mm:ss"];
return [dateFormatter2 stringFromDate:d];
}
else {
return str1;
}
}