问题描述

IOS- “This class is not key value coding-compliant”

在ios应用中声明：

@interface UserRegistrationRequest : BaseServiceRequest@property (nonatomic retain) NSString *username;@property (nonatomic retain) NSString *password;@property (nonatomic retain) NSString *secretQuestionID;@property (nonatomic retain) NSString *secretQuestionAnswer;@property (nonatomic retain) UserProfile *profile;@end@interface UserProfile : NSObject@property (nonatomic retain) NSString *emailAddress;@property (nonatomic retain) NSString *firstName;@property (nonatomic retain) NSString *lastName;@property (nonatomic retain) NSData *profileImage;@property (nonatomic retain) NSNumber *dateOfBirth;@end

我认为这些类应该是键值编码兼容
运行下面的代码：

NSString *propKey = @""profile.firstName"";NSString *propVal = [self.registrationRequest valueForKey:propKey];

报出异常：

[<UserRegistrationRequest 0xb6187f0> valueForUndefinedKey:]: this class is not key value coding-compliant for the key profile.firstName.

不知道应该怎么解决？

解决方案

使用这个：

NSString *propVal = [self.registrationRequest valueForKeyPath:propKey];