我写了一个clearStores方法，遍历每个存储，并从协调器和文件系统中删除它(错误处理不考虑):

NSArray *stores = [persistentStoreCoordinator persistentStores];

for(NSPersistentStore *store in stores) {
    [persistentStoreCoordinator removePersistentStore:store error:nil];
    [[NSFileManager defaultManager] removeItemAtPath:store.URL.path error:nil];
}

[persistentStoreCoordinator release], persistentStoreCoordinator = nil;

这个方法在一个coreDataHelper类中，它负责在persistentStore为nil时创建persistentStore。

你们都把事情搞复杂了。你可以发送你的NSManagedObjectContext重置方法

我写了一个clearStores方法，遍历每个存储，并从协调器和文件系统中删除它(错误处理不考虑):

NSArray *stores = [persistentStoreCoordinator persistentStores];

for(NSPersistentStore *store in stores) {
    [persistentStoreCoordinator removePersistentStore:store error:nil];
    [[NSFileManager defaultManager] removeItemAtPath:store.URL.path error:nil];
}

[persistentStoreCoordinator release], persistentStoreCoordinator = nil;

这个方法在一个coreDataHelper类中，它负责在persistentStore为nil时创建persistentStore。

如果需要删除所有对象且不删除备份文件，可以使用以下方法:

- (void)deleteAllObjectsInContext:(NSManagedObjectContext *)context
                       usingModel:(NSManagedObjectModel *)model
{
    NSArray *entities = model.entities;
    for (NSEntityDescription *entityDescription in entities) {
        [self deleteAllObjectsWithEntityName:entityDescription.name
                                   inContext:context];
    }
}

- (void)deleteAllObjectsWithEntityName:(NSString *)entityName
                             inContext:(NSManagedObjectContext *)context
{
    NSFetchRequest *fetchRequest =
        [NSFetchRequest fetchRequestWithEntityName:entityName];
    fetchRequest.includesPropertyValues = NO;
    fetchRequest.includesSubentities = NO;

    NSError *error;
    NSArray *items = [context executeFetchRequest:fetchRequest error:&error];

    for (NSManagedObject *managedObject in items) {
        [context deleteObject:managedObject];
        NSLog(@"Deleted %@", entityName);
    }
}

注意它可能非常慢(取决于对象图中有多少对象)。

[对请求更新回复的赏金的响应延迟]

回顾之前的答案，

Fetching and deleting all items, as suggested by @Grouchal and others, is still an effective and useful solution. If you have very large data stores then it might be slow, but it still works very well. Simply removing the data store is, as you and @groundhog note, no longer effective. It's obsolete even if you don't use external binary storage because iOS 7 uses WAL mode for SQLite journalling. With WAL mode there may be (potentially large) journal files sitting around for any Core Data persistent store.

But there's a different, similar approach to removing the persistent store that does work. The key is to put your persistent store file in its own sub-directory that doesn't contain anything else. Don't just stick it in the documents directory (or wherever), create a new sub-directory just for the persistent store. The contents of that directory will end up being the persistent store file, the journal files, and the external binary files. If you want to nuke the entire data store, delete that directory and they'll all disappear.

在设置持久化存储时，你会这样做:

NSURL *storeDirectoryURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"persistent-store"];
if ([[NSFileManager defaultManager] createDirectoryAtURL:storeDirectoryURL
        withIntermediateDirectories:NO
        attributes:nil
        error:nil]) {
    NSURL *storeURL = [storeDirectoryURL URLByAppendingPathComponent:@"MyApp.sqlite"];
    // continue with storeURL as usual...
}

然后当你想把商店搬走的时候，

[[NSFileManager defaultManager] removeItemAtURL:storeDirectoryURL error:nil];

这将递归地删除自定义子目录和其中的所有Core Data文件。

这只在您没有将持久存储与其他重要数据放在同一个文件夹中时才有效。比如documents目录，其中可能有其他有用的东西。如果这是您的情况，您可以通过查找您想要保留的文件并删除所有其他文件来获得相同的效果。喜欢的东西:

NSString *docsDirectoryPath = [[self applicationDocumentsDirectory] path];
NSArray *docsDirectoryContents = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:docsDirectoryPath error:nil];
for (NSString *docsDirectoryItem in docsDirectoryContents) {
    // Look at docsDirectoryItem. If it's something you want to keep, do nothing.
    // If it's something you don't recognize, remove it.
}

这种方法可能容易出错。你必须绝对确定你知道你想要保存的每一个文件，否则你可能会删除重要的数据。另一方面，您可以删除外部二进制文件，而不需要知道用于存储它们的文件/目录名称。

Swift 5.1解决方案

public static func reset() {
    let coordinator = _persistentContainer.persistentStoreCoordinator
    for store in coordinator.persistentStores where store.url != nil {
        try? coordinator.remove(store)
        try? FileManager.default.removeItem(atPath: store.url!.path)
    }
}