为NSObject添加非正式协议--catego…

---------------------------------myCategory文件----------------------------
///////////myCategory.h////////

@interface
NSObject(myCategory)
-(void) callFromNSObject;
@end

/////////myCategory.m////////
@implementation
NSObject(myCategory)
-(void) callFromNSObject
{
NSLog(@"i am NSObject
functions");
}
@end
---------------------------------dog文件----------------------------
/////////dog.h//////////
@interface dog
:NSObject
-(void)
init;
@end

////////dog.m///////////
@implementation
dog
-(void) init{};
---------------------------------person文件----------------------------
////////person.h///////
@interface
person:NSObject
{
dog*
mydog;
}
-(void)
call;
@end

////////person.m///////
@implementation
person
-(void)
call{
[mydog callFromNSObject];
}
--------------------------------main文件----------------------------
///////main////////////[/i]
int main(int
argc,const char* argv[])
{
person* p = [[person
alloc]init];
[p
call];
return
0;
}