IOS学习笔记十(多态)

1、多态

相同类型调用同一个方法呈现多种不同的行为特征就是多态

当子类对象直接赋值给父类指针变量，父类 *p = [子类 new];，运行类型是子类，编译类型是父类，所以p不能调用子类单独实现的方法，如果子类重写了父类方法，p调用的方法会是子类重写的方法

isKindOfClass:clazz

判断该对象是否为clazz或者其子类的实例

2、测试demo

KFBase.h

  

   

    

     

    
    

     

      #import <Foundation/Foundation.h>
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      #ifndef KFBase_h
     
    
   

    

     

    
    

     

      #define KFBase_h
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      @interface KFBase : NSObject
     
    
   

    

     

    
    

     

      -(void)base;
     
    
   

    

     

    
    

     

      -(void)test;
     
    
   

    

     

    
    

     

      @end
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      #endif /* KFBase_h */
     
    
  
 

KFBase.m

  

   

    

     

    
    

     

      #import <Foundation/Foundation.h>
     
    
   

    

     

    
    

     

      #import "KFBase.h"
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      @implementation KFBase
     
    
   

    

     

    
    

     

      -(void)base
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     

       NSLog(@"parent base method");
     
    
   

    

     

    
    

     

      }
     
    
   

    

     

    
    

     

      -(void)test
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     

       NSLog(@"parent test method");
     
    
   

    

     

    
    

     

      }
     
    
   

    

     

    
    

     

      @end
     
    
  
 

SubClass.h

  

   

    

     

    
    

     

      #import "KFBase.h"
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      #ifndef Subclass_h
     
    
   

    

     

    
    

     

      #define Subclass_h
     
    
   

    

     

    
    

     

      @interface Subclass : KFBase
     
    
   

    

     

    
    

     

      -(void)sub;
     
    
   

    

     

    
    

     

      -(void)test;
     
    
   

    

     

    
    

     

      @end
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      #endif /* Subclass_h */
     
    
  
 

SubClass.m

  

   

    

     

    
    

     

      #import <Foundation/Foundation.h>
     
    
   

    

     

    
    

     

      #import "Subclass.h"
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      @implementation Subclass
     
    
   

    

     

    
    

     

      -(void)sub
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     

       NSLog(@"child sub method");
     
    
   

    

     

    
    

     

      }
     
    
   

    

     

    
    

     

      -(void)test
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     

       NSLog(@"chile test method");
     
    
   

    

     

    
    

     

      }
     
    
   

    

     

    
    

     

      @end
     
    
  
 

main.m

  

   

    

     

    
    

     

      #import "KFBase.h"
     
    
   

    

     

    
    

     

      #import "Subclass.h"
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      int main(int argc, char * argv[]) {
     
    
   

    

     

    
    

     

       @autoreleasepool {
     
    
   

    

     

    
    

     

       KFBase *base = [KFBase new];
     
    
   

    

     

    
    

     

       [base base];
     
    
   

    

     

    
    

     

       [base test];
     
    
   

    

     

    
    

     

       Subclass *sub = [Subclass new];
     
    
   

    

     

    
    

     

       [sub base];
     
    
   

    

     

    
    

     

       [sub test];
     
    
   

    

     

    
    

     

       [sub sub];
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

       KFBase *seBase = [Subclass new];
     
    
   

    

     

    
    

     

       [seBase base];
     
    
   

    

     

    
    

     

       [seBase test];
     
    
   

    

     

    
    

     

       //下面运行会编译出错
     
    
   

    

     

    
    

     

      // [seBase sub];
     
    
   

    

     

    
    

     

       id dy = seBase;
     
    
   

    

     

    
    

     

       [dy sub];
     
    
   

    

     

    
    

     

      		NSLog(@"sub是KFBase的子类吗？%d",[sub isKindOfClass:[KFBase class]]);
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     

      }
     
    
  
 

3、运行结果

  

   

    

     

    
    

     

      parent base method
     
    
   

    

     

    
    

     

      parent test method
     
    
   

    

     

    
    

     

      parent base method
     
    
   

    

     

    
    

     

      chile test method
     
    
   

    

     

    
    

     

      child sub method
     
    
   

    

     

    
    

     

      parent base method
     
    
   

    

     

    
    

     

      chile test method
     
    
   

    

     

    
    

     

      child sub method
     
    
   

    

     

    
    

     

      sub是KFBase的子类吗？1
     
    
  
 

文章来源: chenyu.blog.csdn.net，作者：chen.yu，版权归原作者所有，如需转载，请联系作者。

原文链接：chenyu.blog.csdn.net/article/details/80954163