iphone - NSInvalidArgumentException/copyWithZone 异常与 NSMutableDictionary

Question

我有一个封装 ABRecordID 的类，当它用作添加到 NSMutableDictionary 的键时，我收到运行时异常:

"NSInvalidArgumentException: *** -[MyRecordId copyWithZone:]: unrecognized selector sent to instance"

MyRecordId 声明为:

@interface MyRecordId : NSObject {
    ABRecordID abRecordId;
}

-(id)initWithId:(ABRecordID)anABRecordId;
@property (nonatomic) ABRecordID abRecordId;

@end

添加到字典:

NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
MyRecordId *recordId = [[MyRecordId alloc] initWithId:anABRecordId];
[dict setObject:@"hello" forKey:recordId];

最后一行导致异常。我知道你不能将非对象类型存储为字典的键，但我认为将其包装在 NSObject 派生类中就可以了。

我不应该将 ABRecordID 存储在其他对象中吗？我应该做点别的吗？

Answer 1

使用 NSNumber 将 ABRecordID 存储在 Obj-C 类中:

[dict setObject:@"hello" forKey:[NSNumber numberWithInt:recordId]];

要再次获取recordId，请执行以下操作:

recordId = [[dict objectForKey:@"hello"] intValue];