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すでに構築されているxmlを取得して解析し、最初にxml内の最も古いアイテムのみを追加し、毎日さらに1つ追加したいと思います。解析に使用されるコードは次のとおりです。

- (void)parseRss:(GDataXMLElement *)rootElement entries:(NSMutableArray *)entries {

    NSArray *channels = [rootElement elementsForName:@"channel"];
    for (GDataXMLElement *channel in channels) {            

        NSString *blogTitle = [channel valueForChild:@"title"];                    

        NSArray *items = [channel elementsForName:@"item"];
        for (GDataXMLElement *item in items) {

            NSString *articleTitle = [item valueForChild:@"title"];
            NSString *articleUrl = [item valueForChild:@"guid"];            
            NSString *articleDateString = [item valueForChild:@"pubdate"];        
            NSDate *articleDate = [NSDate dateFromInternetDateTimeString:articleDateString formatHint:DateFormatHintRFC822];
            NSString *articleImage = [item valueForChild:@"description"];
            NSDateFormatter * dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
            [dateFormatter setTimeStyle:NSDateFormatterShortStyle];
            [dateFormatter setDateStyle:NSDateFormatterMediumStyle];

            RSSEntry *entry = [[[RSSEntry alloc] initWithBlogTitle:blogTitle
                                                      articleTitle:articleTitle
                                                        articleUrl:articleUrl
                                                       articleDate:articleDate
                                                      articleImage:articleImage
                                                              date:thedate] autorelease];
            [entries addObject:entry];

        }      
    }

}

これを変更して、アプリの最初の起動時に最も古いアイテムのみを追加するようにするにはどうすればよいですか？

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1 に答える 1

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AppDelegateのdidFinishLaunchingWithOptionsメソッドに次のように入力しました。

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    if (![defaults integerForKey:@"totalDays"]) {

        // if there is no value for the key, set it to 0
        [defaults setInteger:0 forKey:@"totalDays"];
        [defaults synchronize];
    }
    if (![defaults objectForKey:@"currentDate"]) {
        [defaults setObject:@"32 01" forKey:@"currentDate"];
        //this will ensure that no one's start date ever matches current value
        [defaults synchronize];
    }
    // get the current date
    NSDate *date = [NSDate date];

    // format it
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc]init];
    [dateFormat setDateFormat:@"dd MM"];

    // convert it to a string
    NSString *dateString = [dateFormat stringFromDate:date];

    // free up memory
    [dateFormat release];
    if ([defaults objectForKey:@"currentDate"]){
    NSString *checkdate = [defaults objectForKey:@"currentDate"];
    if (![dateString isEqualToString:checkdate]) {
       //now if your current date is different from the last date it will add 1 to the total days key
        NSInteger currentnumber = [defaults integerForKey:@"totalDays"];
        NSLog(@"The current number is %i", currentnumber);

        [defaults setObject:dateString forKey:@"currentDate"];
        [defaults setInteger:currentnumber+1 forKey:@"totalDays"];
        [defaults synchronize];
        NSLog(@"The new number is %i", [defaults integerForKey:@"totalDays"]);
    }
    }

次に、NSPredicateの領域に次を追加しました。

NSDate *start = [NSDate dateFromRFC3339String:@"2013-01-01T00:00:00-06:00"];
            NSInteger difference = [[NSUserDefaults standardUserDefaults] integerForKey:@"totalDays"];

NSPredicate *predicate = [NSPredicate predicateWithFormat: @"articleDate < %@",  [NSDate dateWithTimeInterval:(86400*difference) sinceDate:start]];
            NSArray *filteredArray = [entries filteredArrayUsingPredicate: predicate];

コードのこの最後のビットは、うまくいけば、当初期待していたことを実行します。

于 2012-12-18T04:55:18.007 に答える