unsigned int count;
      //獲取屬性列表
      objc_property_t *propertyList = class_copyPropertyList([Son class], &count); 
    for (unsigned int i=0; i<count; i++) {
        const char *propertyName = property_getName(propertyList[i]);
        NSLog(@"property---->%@", [NSString stringWithUTF8String:propertyName]);
    }  

 unsigned int count;
 //獲取方法列表
    Method *methodList = class_copyMethodList([Son class], &count);
    for (unsigned int i = 0; i<count ; i++) {
        Method method = methodList[i];
        NSLog(@"method---->%@", NSStringFromSelector(method_getName(method)));
    }

  unsigned int count;
//獲取成員變量列表
    Ivar *ivarList = class_copyIvarList([Son class], &count);
    for (unsigned int i = 0; i<count; i++) {
        Ivar myIvar = ivarList[i];
        const char *ivarName = ivar_getName(myIvar);
        NSLog(@"Ivar---->%@", [NSString stringWithUTF8String:ivarName]);
    }

  unsigned int count;
   //獲取協議列表
    __unsafe_unretained Protocol **protocolList = class_copyProtocolList([Son class], &count);
    for (unsigned int i = 0 ; i<count; i++) {
        Protocol *myProtocal = protocolList[i];
        const char *protocolName = protocol_getName(myProtocal);
        NSLog(@"protocol---->%@", [NSString stringWithUTF8String:protocolName]);
    }

//方法交換
- (void)exchangeMethod {
    //獲得viewController的生命周期方法的selector
    SEL systemSel = @selector(run);
    //自己實現的將要被交換的方法的selector
    SEL mySel = @selector(noRun);
    //兩個方法的Method
    Method systemMethod = class_getInstanceMethod([self class], systemSel);
    Method myMethod = class_getInstanceMethod([self class], mySel);
    
    //首先動態添加方法，實現是被交換的方法，返回值表示添加成功還是失敗
    BOOL isAdd = class_addMethod([Son class], systemSel, method_getImplementation(myMethod), method_getTypeEncoding(myMethod));
    if (isAdd) {
        //如果成功，說明類中不存在這個方法的實現
        //將被交換方法的實現替換到這個并不存在的實現
        class_replaceMethod([Son class], mySel, method_getImplementation(systemMethod), method_getTypeEncoding(systemMethod));
    }else{
        //否則，交換兩個方法的實現
        method_exchangeImplementations(systemMethod, myMethod);
    }
}