Extract a date from a complex NSString

问题

I don't have the ability in Xcode to resolve this problem:

I have this text:

"402 Garcia 01/08/15 10:26 Observaciones del huésped"

And i want to extract the date that i'm sure is GMT +0, then add the phone GMT for example GMT +1 and the replace that old date with the new date inside the NSString.

The GMT stuff i have just solve it in another place so i just need to extract and replace the date string in to the string so my final result will be something like:

"402 Garcia 01/08/15 11:26 Observaciones del huésped"

Any help will be appreciated and thanks in advance.

回答1:

That is exactly what NSDataDetector is there for.

I made a method in a category on NSString:

@interface NSString (HASAdditions)

- (NSArray *)detectedDates;

@end


@implementation NSString (HASAdditions)

- (NSArray *)detectedDates {
    NSError *error = nil;
    NSDataDetector *dateDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeDate error:&error];
    if (!dateDetector) return nil;
    NSArray *matches = [dateDetector matchesInString:self options:kNilOptions range:NSMakeRange(0, self.length)];
    NSMutableArray *dates = [[NSMutableArray alloc] init];
    for (NSTextCheckingResult *match in matches) {
        if (match.resultType == NSTextCheckingTypeDate) {
            [dates addObject:match.date];
        }
    }
    return dates.count ? [dates copy] : nil;
}

You can just call it like this:

NSArray *dates = [@"402 Garcia 01/08/15 10:26 Observaciones del huésped" detectedDates];

You can read more about NSDataDetector over on NSHipster

回答2:

This work is alway is the same text structure.

NSString *text = @"402 Garcia 01/08/15 10:26 Observaciones del huésped";

// This the formatter will be use.
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"dd/MM/yy HH:mm"];
[formatter setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];

// First we extract the part of the text we need.
NSArray *array = [text componentsSeparatedByString:@" "];
NSString *dateString = [NSString stringWithFormat:@"%@ %@",[array objectAtIndex:2],[array objectAtIndex:3]];
// Here the search text
NSLog(@"%@",dateString);

// Now we use the formatter and the extracted text.
NSDate *date = [formatter dateFromString:dateString];

NSLog(@"The date is: %@",[date description]);

来源：https://stackoverflow.com/questions/27861182/extract-a-date-from-a-complex-nsstring

标签

ios

objective-c

string

date

nsstring