我有一个日期字符串,我试图将其转换为 NSDate 以将其与当前日期时间进行比较。我已经尝试实现这一点,但我尝试转换的日期为空值。
这是我尝试过的。
-(BOOL)checkTime{
//create an instance of the database oject
DataBase * dataBase = [[DataBase alloc] init];
//get the times
NSMutableArray *times = [dataBase allDataFrom:@"timings"];
//set date time to string and refresh time to float.
NSString *dateStr = times[1];
float refreshTime = [times[2] floatValue];
// Convert string to date object
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate *date = [dateFormat dateFromString:dateStr];
//get the time now
NSDate* timeNow = [NSDate date];
NSLog(@"dateStr: %@",dateStr);
NSLog(@"DataBase Date: %@",date);
NSLog(@"Current Date: %@",timeNow);
NSLog(@"Time until refresh. (seconds): %f", refreshTime);
// If date is greater than refresh then update the data
if ([timeNow timeIntervalSinceDate:date] > refreshTime)
{
NSLog(@"Data Needs to be checked.");
return YES;
}else{
NSLog(@"Data is fresh.");
return NO;
}
}
这就是我从记录我的所有值中得到的
dateStr: 2013/02/26 12:39:28
DataBase Date: (null)
Current Date: 2013-02-26 12:57:49 +0000
Time until refresh. (seconds): 30.000000
Data is fresh.
我的语法不正确还是我错过了其他东西?