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我正在使用核心数据库将我从网络服务返回的数据保存到我的应用程序中。但这非常非常慢。知道这是怎么来的吗？我要做的是以下。我有一个从 web 服务获取数据的类。就像你在这里看到的那样。

     GenkData.h 

            + (NSArray *)getNews;
     GenkData.m
+ (NSDictionary *)executeGenkFetch:(NSString *)query
{
    query = [NSString stringWithFormat:@"%@", query];
    query = [query stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    // NSLog(@"[%@ %@] sent %@", NSStringFromClass([self class]), NSStringFromSelector(_cmd), query);
    NSData *jsonData = [[NSString stringWithContentsOfURL:[NSURL URLWithString:query] encoding:NSUTF8StringEncoding error:nil] dataUsingEncoding:NSUTF8StringEncoding];
    NSError *error = nil;
    NSDictionary *results = jsonData ? [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers|NSJSONReadingMutableLeaves error:&error] : nil;
    if (error) NSLog(@"[%@ %@] JSON error: %@", NSStringFromClass([self class]), NSStringFromSelector(_cmd), error.localizedDescription);
    // NSLog(@"[%@ %@] received %@", NSStringFromClass([self class]), NSStringFromSelector(_cmd), results);
    return results;
}

+ (NSArray *)getNews
{
    NSString *request = [NSString stringWithFormat:@"http://www.krcgenk.be/mobile/json/request/news/type/ipad"];
    return [[self executeGenkFetch:request] valueForKey:@"news"];
}

然后在我出现的第一个视图控制器中，我有一个方法可以在我的核心数据库中获取我的数据。

- (void)fetchGenkDataIntoDocument:(UIManagedDocument *)document
{
    NSLog(@"Fetch data");
    dispatch_queue_t fetchQ = dispatch_queue_create("Genk fetcher", NULL);
    dispatch_async(fetchQ, ^{

        NSArray *news           = [GenkData getNews];

        [document.managedObjectContext performBlock:^{ // perform in the NSMOC's safe thread (main thread)

            int newsId          = 0;
            //int trainingIndex   = -1;
            for (NSDictionary *genkInfo in news) {
                NSLog(@"Begint met nieuwsitem");
                newsId++;
               [News newsWithGenkInfo:genkInfo inManagedObjectContext:document.managedObjectContext withNewsId:newsId];
                NSLog(@"Einde met nieuwsitem");
            }
 }];
    });
    NSLog(@"einde fethdata");
}

接下来我有一个新闻的 NSManagerd 对象子类的类别，我在其中执行以下操作。

+ (News *)newsWithGenkInfo:(NSDictionary *)genkInfo
    inManagedObjectContext:(NSManagedObjectContext *)context
                withNewsId:(int)newsId
{
    News *news = nil;

    news = [NSEntityDescription insertNewObjectForEntityForName:@"News"
                                                     inManagedObjectContext:context];

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
    [dateFormatter setDateFormat:@"dd/MM/yyyy"];
    [dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"GMT+0:00"]];
        NSDate *date = [dateFormatter dateFromString:[genkInfo objectForKey:NEWS_DATE]];
        news.title              = [genkInfo objectForKey:NEWS_TITLE];
        news.date               = date;
        news.genk_description   = [genkInfo objectForKey:NEWS_DESCRIPTION];
        news.imgurl             = [genkInfo objectForKey:NEWS_IMGURL];
        news.shortdescription   = [genkInfo objectForKey:NEWS_SHORTDESCRIPTION];
        news.url                = [genkInfo objectForKey:NEWS_URL];
        news.imagecopyright     = [genkInfo objectForKey:NEWS_IMAGECOPYRIGHT];
        news.news_id            = [NSNumber numberWithInt:newsId];

    return news;

}

我正在为 10 个不同的实体执行以下过程，例如 10 次。所有这些属性大多是字符串。仍然需要 10 分钟才能加载所有数据。有人可以帮助我吗？

亲切的问候。

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1 回答 1

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Dima 对探查器进行检查的回答帮助我解决了这个问题并解决了我的问题

于 2012-10-30T15:51:10.353 回答