Xcode 将NSString传输到委托时出错

我有一个错误：

[2194:c07] CoreData: error: Failed to call designated initializer on NSManagedObject class 'Event' 
2012-12-08 12:00:57.505 eventCost[2194:c07] -[Event setType:]: unrecognized selector sent to instance 0x7456dd0
2012-12-08 12:00:57.523 eventCost[2194:c07] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Event setType:]: unrecognized selector 

我的addEventController中有协议：@protocol

AddEventControllerDelegate
- (void) addEventControllerDidSave:(NSString *) typeText;
- (void) addEventControllerDidCancel:(Event *) personToDelete;
@end

议定书的执行：

- (void) addEventControllerDidCancel:(Event *)EventToDelete{

    [[self currentPerson] removeEventsObject:EventToDelete];
    [self dismissViewControllerAnimated:YES completion:nil];
}

- (void) addEventControllerDidSave:(NSString *)typeText{

    Event *newEvent = [[Event alloc]init];
    [newEvent setType:typeText];

    [currentPerson addEventsObject:newEvent];
    [self dismissViewControllerAnimated:YES completion:nil];
}

此外，我还有一个添加新事件的序列：

- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{

    if ([[segue identifier]isEqualToString:@"addEvent"])
    {
        AddEventController *aec = (AddEventController *) [segue destinationViewController];
        aec.delegate = self;
    }
}

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我只是尝试添加带有type属性的新事件，但出现了此错误，我不明白出了什么问题。

问题是您试图发送一条

NSManagedObject

init消息

您需要使用

-（id）initWithEntity:（NSEntityDescription*）实体插入ManagedObjectContext:（NSManagedObjectContext*）上下文

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请参阅此处的文档：

显示在“

事件”

”中定义的方法。h接口文件。。。