ios开发——NSCopying与NSMutableCopying协议

 <NSCopying,NSMutableCopying>协议
 
   不是所有的对象都支持copy和mutableCopy,一般自定义的类需要继承NSCopying和NSMutableCopying协议，并对协议中的方法进行实现才满足使用条件。需注意NSObject没有实现这两个协议，但是copy和mutableCopy这两个方法是NSObject定义的. 
加上一句（记得不大清楚了，可以去验证一下），NSString对象若使用mutableCopy,接收到的对象就变成了NSMutableString类型；若继续对这个接收的对象使用一次copy,又会接收到NSString类型。

下面以一个学生类来说明：

 

-----------------interface部分-----------------

@interface DMStudent :NSObject<NSCopying,NSMutableCopying>

......

 

-----------------implementation部分-----------------

#import "DMStudent.h"

@implementation DMStudent

@synthesize dName;

@synthesize dAge;    //assign

@synthesize dSex;

@synthesize dNumber;  //assign

@synthesize dGrade;

@synthesize dInterest;

@synthesize dTeacher;

@synthesize dPhone;  //assign

 

-(void)dealloc{

   [dName
release];
   [dSex
release];
   
[dGrade release];
   
[dInterest release];
   
[dTeacher release]; 
   
[super dealloc]; 
}

//设置多条信息

-(void)setStuInfo:(NSString *)theName andAge:(int)theAgeandSex:(NSString *)theSex andNumber:(int)theNumberandGrade:(NSString *)theGrade andInterest:(NSString *)theInterestandTeacher:(NSString
*)theTeacher andPhone:(int)thePhone{

   
[self setDName:theName];

   
[self setDAge:theAge];

   
[self setDSex:theSex];

   
[self setDNumber:theNumber];

   
[self setDGrade:theGrade];

   
[self setDInterest:theInterest];

   
[self setDTeacher:theTeacher];

   
[self setDPhone:thePhone];    

}

//输出学生信息

-(void)printfInfo{

   NSLog(@"\n----------------");

   NSLog(@"\n姓名：%@",dName);

   NSLog(@"\n年龄：%d",dAge);

   NSLog(@"\n性别：%@",dSex);

   NSLog(@"\n学号：%d",dNumber);

   NSLog(@"\n班级：%@",dGrade);

   NSLog(@"\n爱好：%@",dInterest);

   NSLog(@"\n老师：%@",dTeacher);

   NSLog(@"\n电话：%d",dPhone);  

}

//NSCopying协议，方法实现

-(id)copyWithZone:(NSZone *)zone{

   //先创建一个相同大小的空间；再对该对象以同样的参数初始化，

   
DMStudent *stuCopy = [DMStudent allocWithZone:zone];

   //谁调用方法拷贝，self就表示谁

   
[stuCopy setStuInfo:self.dName andAge:self.dAge andSex:self.dSex andNumber:self.dNumber andRemove:self.dGrade andInterest:self.dInterest andTeacher:self.dTeacher andPoneNumber:self.dPhone];

   
return stuCopy;

}

//NSMutableCopying协议，方法实现

- (id)mutableCopyWithZone:(NSZone *)zone{

   
return [self copyWithZone:zone];

}

 

 

-----------------program部分-----------------

@autoreleasepool {

       DMStudent
*stuOne = [[DMStudent alloc] init] ;

       

       [stuOne
setStuInfo:@"海龟" andAge:1000 andSex:@"公"andNumber:201314520  andGrade:@"海里蹲"andInterest:@"旅游 " andTeacher:@"不详 " andPhone:110];

      

        DMStudent*stuTwo
=[stuOne copy];

                 //这里是深拷贝，拷贝后即便修改之前的信息，对拷贝后的数据没影响；

       [stuOne
setDName:@"小明"];

        [stuTwo
printfInfo];

                 

       DMStudent
*stuThree=[stuOne mutableCopy];

       [stuThree
printfInfo];

     

   
}

   
return0;

}

 

 

 

 

注：不严谨! 条件所限，很多知识点现在还吃不透，日后发现错误再做修改。