从 NSManagedObjectContext 获取数据时出错

Question

我运行我的应用程序，然后获取我的数据。数据没问题。当我第二次跑步时，我的旧价值观出错了。怎么了？

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
 NSEntityDescription *entity = [NSEntityDescription entityForName:@"Test" inManagedObjectContext:[self managedObjectContext]]; 
    for (int i =0; i<2; i++) 
    {
        Test *test = [[[Test alloc] initWithEntity:entity insertIntoManagedObjectContext:[self managedObjectContext]] autorelease];
        test.text = @"Text";
        test.index = [NSNumber numberWithInt:i];
    }
    [self saveContext];
}


-(void) showValues
{    
 NSEntityDescription *entity = [NSEntityDescription entityForName:@"Test" inManagedObjectContext:[self managedObjectContext]];
 NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
 [request setEntity:entity];    
 NSError *error;    
 NSArray *array = [[self managedObjectContext] executeFetchRequest:request error:&error];
 NSLog(@"Array: %@ ", array);    
}

第一次运行

2012-01-22 21:48:52.092 Mew[411:707] Array: (
"<Test: 0x183f60> (entity: Test; id: 0x1856b0 <x-coredata://90165BCF-D2DE-4661-9B12-33EF86F0C09F/Test/p1> ; data: {\n    index = 0;\n    text = Text;\n})",
"<Test: 0x184940> (entity: Test; id: 0x1857e0 <x-coredata://90165BCF-D2DE-4661-9B12-33EF86F0C09F/Test/p2> ; data: {\n    index = 1;\n    text = Text;\n})"
) 

第二次运行 // 第一个和第二个值是错误的

2012-01-22 21:50:29.892 Mew[429:707] Array: (
"<Test: 0x16c950> (entity: Test; id: 0x16c720 <x-coredata://90165BCF-D2DE-4661-9B12-33EF86F0C09F/Test/p1> ; data: <fault>)",
"<Test: 0x16d130> (entity: Test; id: 0x16c730 <x-coredata://90165BCF-D2DE-4661-9B12-33EF86F0C09F/Test/p2> ; data: <fault>)",
"<Test: 0x1684c0> (entity: Test; id: 0x16bfd0 <x-coredata://90165BCF-D2DE-4661-9B12-33EF86F0C09F/Test/p3> ; data: {\n    index = 0;\n    text = Text;\n})",
"<Test: 0x16ab90> (entity: Test; id: 0x16c100 <x-coredata://90165BCF-D2DE-4661-9B12-33EF86F0C09F/Test/p4> ; data: {\n    index = 1;\n    text = Text;\n})"
) 

Answer 1

<fault> 并不意味着您的数据已损坏。这意味着它与获取的结果动态链接，并且当尝试从对象访问任何值/属性时，将加载实际对象。记住 - 你在 .m 文件中使用过@dynamic 吗？ 这就是为什么当您使用数组NSLog 时它显示<fault> 并且当您访问对象NSLog(@"Test: %@ ", test.text); 的任何属性时故障消失了

Answer 2

我修复了一个错误。

我刚刚换了

 NSLog(@"Array: %@ ", array);

到

for (Test *test in array)
{
    NSLog(@"Test: %@ ", test.text);
}

故障消失了