Question

我使用RestKit映射两类对象。当我自己做其中任何一个时，它完全没问题。但是，当我将它们召集在一起时，它会在449，

中的RKObjectMappingOperation.m行崩溃

[destinationSet setSet:destinationObject];

出现"EXC_BAD_ACCESS"错误。

以下是我的两种映射方法：

- (RKObjectLoader *)saves
{
    // Create an object manager and connect core data's persistent store to it
    RKObjectManager *objectManager = [RKObjectManager sharedManager];
    RKManagedObjectStore* objectStore = [RKManagedObjectStore objectStoreWithStoreFilename:@"Db.sqlite"];
    objectManager.objectStore = objectStore;

    // Define our author mapping for saved places
    RKManagedObjectMapping *authorMapping = [RKManagedObjectMapping mappingForEntityWithName:@"Person"];
    [authorMapping mapAttributes:@"uid", nil];

    // Define our place mapping
    RKManagedObjectMapping *placeMapping = [RKManagedObjectMapping mappingForEntityWithName:@"Place"];
    [placeMapping mapAttributes:@"uid",@"name",@"address", nil];

    // Now, connect the two via a save
    RKManagedObjectMapping *saveMapping = [RKManagedObjectMapping mappingForEntityWithName:@"Save"];
    [saveMapping mapAttributes:@"uid", @"timestamp", nil];

    [saveMapping mapKeyPath:@"place" toRelationship:@"place" withMapping:placeMapping];
    [saveMapping mapKeyPath:@"author" toRelationship:@"author" withMapping:authorMapping];

    // We expect to find the place entity inside of a dictionary keyed "saves"
    [objectManager.mappingProvider setMapping:saveMapping forKeyPath:@"saves"];

    // Prepare our object loader to load and map objects from remote server, and send
    RKObjectLoader *objectLoader = [objectManager objectLoaderWithResourcePath:@"places/saves" delegate:self];
    objectLoader.method = RKRequestMethodGET;
    [objectLoader send];

    return objectLoader;
}

- (RKObjectLoader *)recommends
{
    // Create an object manager and connect core data's persistent store to it
    RKObjectManager *objectManager = [RKObjectManager sharedManager];
    RKManagedObjectStore* objectStore = [RKManagedObjectStore objectStoreWithStoreFilename:@"Db.sqlite"];
    objectManager.objectStore = objectStore;

    // Define our author mapping for recommended places
    RKManagedObjectMapping *authorMapping = [RKManagedObjectMapping mappingForEntityWithName:@"Person"];
    [authorMapping mapAttributes:@"uid", nil];

    // Define our place mapping
    RKManagedObjectMapping *placeMapping = [RKManagedObjectMapping mappingForEntityWithName:@"Place"];
    [placeMapping mapAttributes:@"uid",@"name",@"address", nil];

    // Now, connect the two via a recommend
    RKManagedObjectMapping *recommendMapping = [RKManagedObjectMapping mappingForEntityWithName:@"Recommend"];
    [recommendMapping mapAttributes:@"uid", @"timestamp", nil];

    [recommendMapping mapKeyPath:@"place" toRelationship:@"place" withMapping:placeMapping];
    [recommendMapping mapKeyPath:@"author" toRelationship:@"author" withMapping:authorMapping];

    // We expect to find the place entity inside of a dictionary keyed "recommends"
    [objectManager.mappingProvider setMapping:recommendMapping forKeyPath:@"recommends"];

    // Prepare our object loader to load and map objects from remote server, and send
    RKObjectLoader *objectLoader = [objectManager objectLoaderWithResourcePath:@"places/recommends" delegate:self];
    objectLoader.method = RKRequestMethodGET;
    [objectLoader send];

    return objectLoader;
}

当我呼叫一个或另一个时，它起作用。当我同时打电话时，

[self saves];
[self recommends];

它崩溃了。知道为什么吗？

Answer 1

设置objectManager.objectStore的调用导致之前设置的objectStore从objectManager释放。第一个调用[self saves]创建并设置objectStore个对象，然后第二个调用[self recommends]重复此操作，从而删除[self saves]中的第一个集。在[self saves]开始处理的一段时间内，正在访问原始（已发布的）objectStore对象，因此崩溃。

可能的解决方法是将objectStore setter重构为一个单独的方法，该方法由两个方法调用，或者将它包装在if (!objectManager.objectStore) { ... }语句中。

Restkit对象映射两个类访问不良

1 个答案: