如何在协议中定义和实现属性

Question

我想定义一个具有很少属性的协议,并且需要在另一个NSObject子类中使用这些属性.请给我链接或示例代码.我需要与10.5合作.

谢谢请检查以下示例代码

@protocol MyProtocol
@property (nonatomic, readonly) id someObject;
@property (nonatomic, getter=isAlive) BOOL alive;
@end

#import "MyProtocol.h"
@interface MyCustomClass : NSObject <MyProtocol>{

}
@end

#import "MyCustomClass.h"
@implementation MyCustomClass
@synthesize someObject,alive;

/*
- (id)someObject {
    return nil;
}

- (BOOL)isAlive {
    return YES;
}

- (void)setAlive:(BOOL)aBOOL {
}
*/
@end

**补充:使用x86_64架构编译代码工作正常.但如果我将架构更改为i386,则会出现错误,然后我收到以下警告:

MyCustomClass.m:13: error: synthesized property 'someObject' must either be named the same as a compatible ivar or must explicitly name an ivar

 error: synthesized property 'alive' must either be named the same as a compatible ivar or must explicitly name an ivar

我只想知道它为什么在x86_64中使用@synthesize而不是在i386中工作.**

Answer 1

@property 只是对编译器说,该类应该定义匹配该属性的方法.

@protocol MyProtocol
@property (nonatomic, readonly) id someObject;
@property (nonatomic, getter=isAlive) BOOL alive;
@end

现在需要实现该协议的任何东西

- (id)someObject;
- (BOOL)isAlive;
- (void)setAlive:(BOOL)aBOOL;