Objective-C:动态绑定

 //  Complex.h
 //  03-动态绑定
 //
 //  Created by ma c on 15/8/11.
 //  Copyright (c) 2015年. All rights reserved.
 //

 #import <Foundation/Foundation.h>

 @interface Complex : NSObject
 @property(nonatomic,assign)CGFloat real;//实部
 @property(nonatomic,assign)CGFloat imag;//虚部
 -(instancetype)initWithReal:(CGFloat)r andImag:(CGFloat)i;
 -(Complex *)add:(Complex *)c;
 -(void)print;
 @end

 //  Complex.m
 //  03-动态绑定
 //
 //  Created by ma c on 15/8/11.
 //  Copyright (c) 2015年 bjsxt. All rights reserved.
 //

 #import "Complex.h"

 @implementation Complex
 -(instancetype)initWithReal:(CGFloat)r andImag:(CGFloat)i
 {
     self = [super init];
     if(self)
     {
         _real = r;
         _imag = i;
     }
     return self;
 }
 -(Complex *)add:(Complex *)c
 {
     CGFloat r = _real+c.real;
     CGFloat i = _imag+c.imag;
     return [[Complex alloc]initWithReal:r andImag:i];
 }
 -(void)print
 {
     NSLog(@"%.2f*%.2fi",_real,_imag);
 }
 @end

 //  Fraction.h
 //  03-动态绑定
 //
 //  Created by ma c on 15/8/11.
 //  Copyright (c) 2015年. All rights reserved.
 //

 #import <Foundation/Foundation.h>

 @interface Fraction : NSObject

 @property(nonatomic,assign)NSInteger numerator;//分子
 @property(nonatomic,assign)NSInteger denominator;//分母
 -(id)initWithNumerator:(NSInteger)n addDenominator:(NSInteger) d;
 -(Fraction*) add:(Fraction*) fraction;
 -(void)print;
 @end

 //  Fraction.m
 //  03-动态绑定
 //
 //  Created by ma c on 15/8/11.
 //  Copyright (c) 2015年 bjsxt. All rights reserved.
 //

 #import "Fraction.h"

 @implementation Fraction
 -(id)initWithNumerator:(NSInteger)n addDenominator:(NSInteger) d
 {
     self = [super init];
     if(self)
     {
         _numerator = n;
         _denominator = d;
     }
     return self;
 }
 -(Fraction*) add:(Fraction*) fraction
 {
    NSInteger n = _numerator*fraction.denominator+fraction.numerator*_denominator;
    NSInteger d = _denominator*fraction.denominator;

    return [[Fraction alloc]initWithNumerator:n addDenominator:d];
 }
 -(void)print
 {
     NSLog(@"%ld/%ld",_numerator,_denominator);
 }
 @end

 //  main.m
 //  03-动态绑定
 //
 //  Created by ma c on 15/8/11.
 //  Copyright (c) 2015年. All rights reserved.
 //

 #import <Foundation/Foundation.h>
 #import "Fraction.h"
 #import "Complex.h"
 int main(int argc, const char * argv[])
 {
     @autoreleasepool
     {
         //测试分数类
         Fraction *f1 = [[Fraction alloc]initWithNumerator:
                                            addDenominator:];
         [f1 print];

         Fraction *f2 = [[Fraction alloc]initWithNumerator:
                                            addDenominator:];
         [f2 print];

         Fraction *f3 = [f1 add:f2];
         [f3 print];

         //测试复数类
         Complex *c1 = [[Complex alloc]initWithReal:5.0 andImag:3.0];
         [c1 print];

         Complex *c2 = [[Complex alloc]initWithReal:4.3 andImag:2.5];
         [c2 print];

         Complex *c3 = [c1 add: c2];
         [c3 print];

         //测试动态绑定
         id pObj = nil;
         pObj = f3;
         [f3 print];

         pObj = c3;
         [c3 print];

         id arr[] = {c1,f1,@""};
         for(int i=;i<;i++)
         {
             //运行时检查
             /*if([arr[i] isKindOfClass:[Fraction class]]==YES || [arr[i] isKindOfClass:[Complex class]]==YES)
             */
             if([arr[i] respondsToSelector:@selector(print)]==YES)
             {
               [arr[i] print];
               //SEL sel = @selector(print);
               //[arr[i] performSelector:@selector(print)];
             }

         }
     }
     return ;
 }