NScoder objective-c运行时

Question

NSCoder *coder; 
coder=[[NSCoder alloc]init];
[coder encodeObject:@"value" forKey:@"frame"];

错误

  

由于未捕获的异常终止应用程序＆＃39; NSInvalidArgumentException＆＃39;，原因：＆＃39; *** -encodeObject：forKey：无法发送到类NSCoder的抽象对象：创建一个具体的实例！`< / p>

这在运行时间中断了。任何人都帮我找到它我做错了什么？

Answer 1

需要创建一个模型类，并且在这个模型类中，需要实现一个NSCodingProtocol

例如Book Class

Book.h

@interface Book : NSObject<NSCoding>

@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) NSString *author;

@end

Book.m

- (id)initWithCoder:(NSCoder *)aDecoder {
    if (self = [super init]) {
        self.title = [aDecoder decodeObjectForKey:@"name"];
        self.author = [aDecoder decodeObjectForKey:@author"];
    }
    return self;
}

- (void)encodeWithCoder:(NSCoder *)aCoder {
    [aCoder encodeObject:_name forKey:@"name"];
    [aCoder encodeObject:_author forKey:@"author"];
}