Runtime

https://www.jianshu.com/p/6ebda3cd8052

开发中可能用到的Runtime：在Category中添加属性， 交换方法的实现，归档接档（获取所用的变量， 属性， 方法名， 协议名），动态添加方法

1：添加属性

objc_setAssociatedObject(self, _cmd, girlFriend, OBJC_ASSOCIATION_RETAIN);

objc_getAssociatedObject(self, @selector(setGirlFriend:));

2：方法交换

+ (void)MethodSwapWithSEL:(SEL)sel1 otherSEL:(SEL)sel2 {
    Method fromMethod = class_getInstanceMethod([self class], sel1);
    Method toMethod = class_getInstanceMethod([self class], sel2);
    method_exchangeImplementations(fromMethod, toMethod);
}

3：获取所有的变量，属性，方法， 协议名

    /// 变量
    unsigned int count = 0;
    Ivar *ivarList = class_copyIvarList([People class], &count);
    for (int i = 0; i < count; i++) {
        // 变量的名
        NSString *ivarName = [NSString stringWithUTF8String:ivar_getName(ivarList[i])];
        // 变量的类型
        NSString *ivarType = [NSString stringWithUTF8String:ivar_getTypeEncoding(ivarList[i])];
    }

    unsigned int count = 0;
    /// 属性
    objc_property_t *propertyList = class_copyPropertyList([People class], &count);
    /// 方法
    Method *methodList = class_copyMethodList([People class], &count);
    /// 协议
    class_copyProtocolList([People class], &count);

4 动态添加方法

+ (BOOL)resolveClassMethod:(SEL)sel {
    
}

+ (BOOL)resolveInstanceMethod:(SEL)sel {
    
}

 重定向

- (id)forwardingTargetForSelector:(SEL)aSelector {
    
}

 转发

- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector {
    
}

- (void)forwardInvocation:(NSInvocation *)anInvocation {
    
}