我创建类:

@interface KVOGame : NSObject

@property (nonatomic, strong) NSString *name;
@property (nonatomic, strong) NSString *releaseDate;
@property (nonatomic, strong) KVOPlatform *platform;

@end


另一个属性:

@interface KVOPlatform : NSObject

@property (nonatomic, strong) NSString *platformName;
@property (nonatomic, strong) NSString *platformVersion;

@end


然后我尝试使用KVC来获取“ platformVersion”,如下所示

@interface KVOViewController ()

@end

@implementation KVOViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    KVOGame *game = [[KVOGame alloc] init];
    game.name = @"Bayonetta";
    game.releaseDate = @"8.10.2009";
    game.platform.platformName = @"PS3, Xbox360";
    game.platform.platformVersion = @"all versions";

    NSString *identifier = @"platform.platformVersion";

    NSLog(@"%@", [game valueForKey:identifier]);
}


它崩溃并显示错误:


  由于未捕获的异常'NSUnknownKeyException'而终止应用程序,原因:'[valueForUndefinedKey:]:此类与密钥platform.platformVersion的编码都不兼容。


我究竟做错了什么?

更新:valueForKeyPath:而不是valueForKey也不起作用-仍然崩溃。

最佳答案

尝试NSLog(@"%@", [game valueForKeyPath:identifier]);

我假设game.platform永远不会被创建。零

关于ios - KVC点键问题,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/23576871/

10-10 20:28