Convert NSString of a date to an NSDate

问题

This might be a silly question, but I can't seem to find the answer on here or in the documentation.

I want to convert an NSString such as @"9/22/2010 3:45 PM" to an NSDate.

I know to use NSDateFormatter, but the problems are

1. The month could be one or two digits
2. Likewise, the date could be one or two digits
3. Hours could be one or two digits
4. What do I do about AM/PM?

回答1:

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"MM/dd/yyyy h:mm a"];
NSDate *date = [dateFormat dateFromString:dateStr];
[dateFormat release];

there is no problem in 2 digit day or 2 digit month.

This must help you.

回答2:

You can parse an NSString into an NSDate using the NSDateFormatter class. See the documentation for more info:

Instances of NSDateFormatter create string representations of NSDate (and NSCalendarDate) objects, and convert textual representations of dates and times into NSDate objects.

回答3:

I was having the same problem, not sure why NSDateFormatter isn't working for me (iOS5 - Xcode 4.3.2) but this worked out for me:

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]];
[dateFormatter setDateFormat:@"dd-MM-yyyy"];
NSString *dateString = @"05-06-2012";
NSDate *date;
NSError *error = nil; 
if (![dateFormatter getObjectValue:&date forString:dateString range:nil error:&error]) {
    NSLog(@"Date '%@' could not be parsed: %@", dateString, error);
}
[dateFormatter release];

来源：https://stackoverflow.com/questions/4332319/convert-nsstring-of-a-date-to-an-nsdate