CoreData写对象慢 [英] CoreData writing objects slow

问题描述

我正在从Web服务下载地址列表（15.000个地址）。获取所有地址可能需要800毫秒，而将它们写入CoreData则需要额外的15秒。请在错误之处提供一些建议：

I'm downloading list of addresses from the webservice(15.000 addresses). It took maybe 800ms to get all addresses and additional 15 seconds to write them to CoreData. Please give some advice where I am wrong:

AppDelegate *delegate = [[UIApplication sharedApplication] delegate];
            NSManagedObjectContext *managedObjectContext = delegate.managedObjectContext;
            for (NSDictionary *dict in addresses) {
                [self saveAddressesToCoreDataWithDictionary:dict andManagedObject:managedObjectContext];
            }
            [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"alreadyDownloaded"];

和方法：

-(void)saveAddressesToCoreDataWithDictionary:(NSDictionary *)dict andManagedObject:(NSManagedObjectContext *)managedObject
{

    NSManagedObject *address;
    address = [NSEntityDescription insertNewObjectForEntityForName:@"Address" inManagedObjectContext:managedObject];

    [address setValue:[[dict objectForKey:@"lat"] stringValue] forKey:@"lat"];
    [address setValue:[[dict objectForKey:@"lon"] stringValue] forKey:@"lon"];
    [address setValue:[dict objectForKey:@"addressLong"] forKey:@"addressLong"];
    [address setValue:[dict objectForKey:@"addressShort"] forKey:@"addressShort"];
    NSError *error;
    [managedObject save:&error];

}

推荐答案

！

问题是我每次都保存了managedObjectContext，并且应该仅在迭代完成后才保存。

Problem was that I was saving managedObjectContext everytime, and it should be saved only when iteration is finished.

仅移动了这一行：

if ([managedObjectContext save:&error] == NO) {
                NSAssert(NO, @"Error saving context: %@\n%@", [error localizedDescription], [error userInfo]);
            }

以下循环。

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