oc runtime记动态添加属性、交换方法

#import <objc/runtime.h>

#ifndef DYNAMIC_PROPERTY_OBJECT
#define DYNAMIC_PROPERTY_OBJECT(_getter_, _setter_, _association_, _type_) \
- (void)_setter_ : (_type_)object { \
    [self willChangeValueForKey:@#_getter_]; \
    objc_setAssociatedObject(self, _cmd, object, OBJC_ASSOCIATION_ ## _association_); \
    [self didChangeValueForKey:@#_getter_]; \
} \
- (_type_)_getter_ { \
    return objc_getAssociatedObject(self, @selector(_setter_:)); \
}
#endif

void swizzlingMethod(Class c, SEL origSEL, SEL newSEL);

void swizzlingMethod(Class class, SEL originSEL, SEL swizzledSEL)
{
    Method originMethod = class_getInstanceMethod(class, originSEL);
    Method swizzledMethod = nil;
    
    if (!originMethod) {// 处理为类方法
        originMethod = class_getClassMethod(class, originSEL);
        if (!originMethod) {
            return;
        }
        swizzledMethod = class_getClassMethod(class, swizzledSEL);
        if (!swizzledMethod) {
            return;
        }
    }else {// 处理实例方法
        swizzledMethod = class_getInstanceMethod(class, swizzledSEL);
        if (!swizzledMethod){
            return;
        }
    }
    
    if(class_addMethod(class, originSEL, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod))){
        class_replaceMethod(class, swizzledSEL, method_getImplementation(originMethod), method_getTypeEncoding(originMethod));
    }else {
        //自身已经有了就添加不成功，直接交换即可
        method_exchangeImplementations(originMethod, swizzledMethod);
    }
}