Question

我是新手，从头开始学习核心数据。我已经设置了coredatamodel，然后创建了NSManagedObject类。然后在app委托中，我试图插入一些测试数据。但是，它无法正常工作。仅插入了最后一个数据。我应该放

[self saveContext];

在每个物体之间？在“applicationWillTerminate”方法中，调用saveContext方法，因此保存了最后一项。（这是正确的吗？）

NSManagedObjectContext *context = [self managedObjectContext];

Vocabulary *vocabulary = [NSEntityDescription
                                   insertNewObjectForEntityForName:@"Vocabulary" 
                                   inManagedObjectContext:context];

vocabulary.word = @"iPhone";
vocabulary.definition = @"better than Android";
vocabulary.level = @"beginner";

vocabulary.word = @"iPhone3gs";
vocabulary.definition = @"better than 3";
vocabulary.level = @"intermediate";

vocabulary.word = @"iPhone4";
vocabulary.definition = @"better than 3gs";
vocabulary.level = @"advanced";

vocabulary.word = @"iPhone4s";
vocabulary.definition = @"better than 4";

vocabulary.word = @"iPhone4s";
vocabulary.definition = @"64 is better than 32";
vocabulary.level = @"advanced";

Answer 1

您需要为插入的每个词汇表对象插入一个新实体。所以这样做：

Vocabulary *vocabulary = nil;
NSManagedObjectContext *context = [self managedObjectContext];

vocabulary = [NSEntityDescription insertNewObjectForEntityForName:@"Vocabulary" inManagedObjectContext:context];
vocabulary.word = @"iPhone";
vocabulary.definition = @"better than Android";
vocabulary.level = @"beginner";

vocabulary = [NSEntityDescription insertNewObjectForEntityForName:@"Vocabulary" inManagedObjectContext:context];
vocabulary.word = @"iPhone3gs";
vocabulary.definition = @"better than 3";
vocabulary.level = @"intermediate";

vocabulary = [NSEntityDescription insertNewObjectForEntityForName:@"Vocabulary" inManagedObjectContext:context];
vocabulary.word = @"iPhone4";
vocabulary.definition = @"better than 3gs";
vocabulary.level = @"advanced";

vocabulary = [NSEntityDescription insertNewObjectForEntityForName:@"Vocabulary" inManagedObjectContext:context];
vocabulary.word = @"iPhone4s";
vocabulary.definition = @"better than 4";

vocabulary = [NSEntityDescription insertNewObjectForEntityForName:@"Vocabulary" inManagedObjectContext:context];
vocabulary.word = @"iPhone4s";
vocabulary.definition = @"64 is better than 32";
vocabulary.level = @"advanced";

使用Core Data添加多个测试数据

1 个答案: