Question

可能我的问题看起来很奇怪，但是......（希望有人帮助我）

我从FTP加载一些数据有两种方法。有时应用程序会依赖这些方法。

检查互联网连接。

如果互联网可用：

@interface Download : NSObject {
    NSOperationQueue *operationQueue;
}

...

if (!operationQueue) {
    operationQueue = [NSOperationQueue new];
}

NSInvocationOperation *operation1;
operation1 = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(loadIngredientsFromJSON) object:nil];
[operationQueue addOperation:operation1];

NSInvocationOperation *operation2;
operation2 = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(loadRecipesFromJSON) object:nil];
[operation2 addDependency:operation1];
[operationQueue addOperation:operation2];

[operationQueue addObserver:self forKeyPath:@"operations" options:0 context:NULL];

方法 loadIngredientsFromJSON ＆amp;的 loadRecipesFromJSON

-(void) loadIngredientsFromJSON
{
    NSInteger countInBase = [self dataCountInEntity:@"Ingredients"];

    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"ftp://...Ingredients.json"]];
    NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

    NSError *error = nil;
    if (!responseData) {
        return;
    }

    NSDictionary *ingredientsDictionary = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
    if (!ingredientsDictionary) {
       return;
    }

    //NSLog(@"%@", [ingredientsDictionary description]);

    NSArray *keys = [ingredientsDictionary allKeys];
    if (!countInBase && [ingredientsDictionary count]>0) {
    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    for (int i=0; i<[ingredientsDictionary count]; i++) {
       id aKey = [keys objectAtIndex:i];
       NSArray *ingrData = [ingredientsDictionary objectForKey:[NSString stringWithFormat:@"%@", aKey]];
       NSArray *tmpArray = [NSArray arrayWithObjects:aKey, [ingrData objectAtIndex:0], [ingrData objectAtIndex:1], nil];
       Ingredients *ingredient = [NSEntityDescription insertNewObjectForEntityForName:@"Ingredients" inManagedObjectContext:appDelegate.managedObjectContext];

       ingredient.code = [NSNumber numberWithInteger:[[tmpArray objectAtIndex:0] integerValue]];
       ingredient.name = [tmpArray objectAtIndex:1];
       ingredient.units = [tmpArray objectAtIndex:2];
       ingredient.type = [NSNumber numberWithInt:1];
       [appDelegate.managedObjectContext save:nil];
    }
    }
}

...

    - (void) loadRecipesFromJSON
    {        
       NSInteger missedCount = 0;
       NSInteger recipeCode = 0;
       NSString *recipesPath = @"ftp://...";

       do {
         recipeCode ++;
         NSString *recipeFileName = [NSString stringWithFormat:@"recipes/%05d.json", recipeCode];
         NSString *recipeFileFullPath = [recipesPath stringByAppendingString:recipeFileName];

         NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:recipeFileFullPath]];
         NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
         NSError *error = nil;
         if (!responseData) {
            missedCount ++;
            continue;
         }
         NSDictionary *recipeDictionary = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];
         if (!recipeDictionary) {
            missedCount ++;
            continue;
         }

         AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];

         NSInteger recipeCount = [self isDataExistInEntity:@"Recipes" withCode:[[recipeDictionary objectForKey:@"recipeCode"] integerValue]];
    if (recipeCount == 0) {
        Recipes *recipe = [NSEntityDescription insertNewObjectForEntityForName:@"Recipes" inManagedObjectContext:appDelegate.managedObjectContext];
        recipe.code = [recipeDictionary objectForKey:@"recipeCode"];
        recipe.dateUpdated = [recipeDictionary objectForKey:@"dateEdited"];
        recipe.inCategory = [recipeDictionary objectForKey:@"inCategory"];
        recipe.name = [recipeDictionary objectForKey:@"recipe"];
        recipe.difficulty = [recipeDictionary objectForKey:@"difficulty"];
        recipe.personCount = [recipeDictionary objectForKey:@"personCount"];
        recipe.prepHour = [recipeDictionary objectForKey:@"prepHour"];
        recipe.prepMin = [recipeDictionary objectForKey:@"prepMin"];
        int seconds = ([recipe.prepMin intValue]*60)+([recipe.prepHour intValue] * 60 * 60);
        recipe.prepTime = [NSNumber numberWithInt: seconds];
        recipe.isPaid = [recipeDictionary objectForKey:@"isPaid"];
        recipe.comment = [recipeDictionary objectForKey:@"comments"];

        NSDictionary *ingredients = [recipeDictionary objectForKey:@"ingredients"];
        NSArray *keys = [ingredients allKeys];
        if ([keys count] > 0) {
            for (int i=0; i<[keys count]; i++) {
                Join *join = [NSEntityDescription insertNewObjectForEntityForName:@"Join" inManagedObjectContext:appDelegate.managedObjectContext];
                join.recipeCode = [recipeDictionary objectForKey:@"recipeCode"];

                id aKey = [keys objectAtIndex:i];
                join.ingredientCode = [NSNumber numberWithInteger:[aKey integerValue]];

                NSString *str = [ingredients objectForKey:aKey];
                double num = [str doubleValue];
                join.count = [NSNumber numberWithDouble:num];

                join.inCart = [NSNumber numberWithInt:0];
            }
        }

        NSDictionary *prepStages = [recipeDictionary objectForKey:@"prepStage"];
        keys = [prepStages allKeys];
        if ([keys count] > 0) {
            for (int i=0; i<[keys count]; i++) {
                PrepStages *prepStage = [NSEntityDescription insertNewObjectForEntityForName:@"PrepStages" inManagedObjectContext:appDelegate.managedObjectContext];
                prepStage.recipeCode = [recipeDictionary objectForKey:@"recipeCode"];

                id aKey = [keys objectAtIndex:i];
                prepStage.order = [NSNumber numberWithInteger:[aKey integerValue]];
                prepStage.descriptions = [prepStages objectForKey:aKey];

                //загрузка картинки
                NSString *recipeImageName = [NSString stringWithFormat:@"recipeImages/%05d-%@.jpg", recipeCode, [NSNumber numberWithInteger:[aKey integerValue]]];
                NSString *recipeImageFullPath = [recipesPath stringByAppendingString:recipeImageName];
                NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:recipeImageFullPath]];
                if (request) {
                    NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

                    if (responseData) {
                        UIImage *image = [UIImage imageWithData:responseData];
                        prepStage.image = image;
                    }
                }

            }
        }
        [appDelegate.managedObjectContext save:nil];
    }
    else {
        missedCount ++;
        continue;
    }

    } while (missedCount < 10);
    }

有时，在这两种方法之一中，应用程序挂起并控制冻结。

任何人都可以给我一些建议，说明可能存在错误。

我很困惑......

EDITED

我注意到有趣的事情：

下载过程在应用运行时启动。它从服务器下载 Recipes 并将其插入CoreData。如果我点按食谱列表，我会使用appDelegate.managedObjectContext来获取数据。当想要插入数据时，下载也会使用appDelegate.managedObjectContext。

这可能包含问题吗？

应用程序挂起从FTP加载JSON，序列化并保存到Core Data [iOS]

0 个答案: