Objective c 我不知道如何从字符串数组（parentRootItems）中获取对象，而是使用此代码获取对象

我不知道如何从parentRootItems的字符串数组中获取对象，我使用以下代码：

NSArray *parentRootItems = [pFolder rootItems];
NSLog(@"parentRootItems %@", [parentRootItems description]);

NSString *keyPath = [NSString stringWithFormat:@"@distinctUnionOfObjects.%@", metadata.lookupItemsKeyPath];
NSLog(@"keyPath %@", keyPath);

NSArray *managedItems = [parentRootItems valueForKeyPath:keyPath];
NSLog(@"managedItems %@", [managedItems description]);

谢谢

输出

parentRootItems (Self-Inflicted Wounds / Rebirth)
                (Self-Inflicted Wounds / Rebirth)
                ...


keyPath @distinctUnionOfObjects.Series

 managedItems (
    <CBSeries: 0x1ddf3c0> (entity: Series; id: 0x1ddf260 <x-coredata://2B6F6719-9BCB-4C5C-B027-0DE2C7C1910C/Series/p350> ; data: {
    ClzID = 37268;
    Comics = "<relationship fault: 0x1de3790 'Comics'>";
    Complete = 0;
    DisplayName = Annihilators;
    Frequency = nil;
    ISSN = nil;
    Image = nil;
    Name = nil;
    NumIssues = 0;
    SortName = Annihilators;
    Stories = "<relationship fault: 0x1de39c0 'Stories'>";
    The = nil;
    URL = nil;
    UniqueID = 1;
}),
    <CBSeries: 0x1dd2940> (entity: Series; id: 0x1db4b60 <x-coredata://2B6F6719-9BCB-4C5C-B027-0DE2C7C1910C/Series/p354> ; data: {
    ClzID = 3856;
    Comics = "<relationship fault: 0x1de4230 'Comics'>";
    Complete = 0;
    DisplayName = Futurama;
    Frequency = nil;
    ISSN = nil;
    Image = nil;
    Name = nil;
    NumIssues = 0;
    SortName = Futurama;
    Stories = "<relationship fault: 0x1de4510 'Stories'>";
    The = nil;
    URL = nil;
    UniqueID = 9;
}),
...

parentRootItems不是字符串数组。从外观上看，它是一个托管对象数组，每个对象都有一个.Series属性，该属性指向Series实体的另一个托管对象

您将返回一个数组，其中包含parentRootItems中的对象使用的每个系列实体，并删除所有重复项

要更清楚地查看parentRootItems中的内容，请使用以下日志消息，而不是您当前正在执行的描述：

NSLog(@"Parent root items: %@",parentRootItems);