为什么我在Objective-C中声明根类时会出现错误？

Question

例:

@class MyRootObject;

@interface MyObject : MyRootObject
@end

获取表单XCode:

Class MyObject defined without specifying a base class.

MyRootObject类是:

@interface MyRootObject : NSObject

- (id)init;

@end

@implementation MyRootObject

- (id)init
{
   self = [super init];

   if(self){
      // some code here
   }

   return self;
}

@end

Answer 1

您不能从前向声明的类继承.您需要#include使用相应的标头.