Objective-c SEL & Class IMP

Classes (class type) in OBJC (objective-c), Selector (selector sel), function pointer (IMP) I saw a cow in the garden today "OBJECTIVE-C 2.0 with Cocoa Foundation--- The 5,class type, selector selector, and function pointer are very exciting, and can not help but annotate its code with annotations for later viewing. Personal experience: The "class type variable" in OBJ-C is more flexible than the object base class in C #, and it can be used to generate any type of instance (but it is not nsobject). and the selector sel and the function pointer imp, if you want to have a relationship with C #, these two combine, on the point similar to the Reflection + delegate in C #, you can invoke the method directly according to a method name string. "OX" base class Cattle.h View source print?

1	#import <Foundation/Foundation.h>

2

3	@interface Cattle: nsobject {

4	int legscount;

5

}

6	-(void) saysomething;

7	-(void) Setlegscount: (int) count;

8

@end

CATTLE.M View Source print?

01	#import "Cattle.h"

02

03	@implementation Cattle

04

05	-(void) saysomething

06

{

07	NSLog (@ "Hello, I am a cattle, I have%d legs.", legscount);

08

}

09

10	-(void) Setlegscount: (int) count

11

{

12	Legscount = count;

13

}

14

@end

Subclass "Bull" Bull.h View source print?

01	#import <Foundation/Foundation.h>

02	#import "Cattle.h"

03

04	@interface Bull:cattle {

05	nsstring *skincolor;

06

}

07	-(void) saysomething;

08	-(nsstring*) Getskincolor;

09	-(void) Setskincolor: (nsstring *) color;

10

@end

BULL.M View Source print?

01	#import "Bull.h"

02

03

04	@implementation Bull

05

06	-(void) saysomething

07

{

08	NSLog (@ "Hello, I am a%@ bull, I have%d legs.", [self getskincolor],legscount);

09

}

10

11	-(nsstring*) getskincolor

12

{

13	return skincolor;

14

}

15

16	-(void) Setskincolor: (nsstring *) color

17

{

18	Skincolor = color;

19

}

20

@end

Proxy class DoProxy.h (here's the key code) View source print?

01	#import <Foundation/Foundation.h>

02

03	Defining several string constants

04	#define Set_skin_color @ "Setskincolor:"

05	#define BULL_CLASS @ "BULL"

06	#define CATTLE_CLASS @ "cattle"

07

08

09	@interface Doproxy: nsobject {

10	BOOL Notfirstrun;

11

12	ID Cattle[3];

13	Define two selectors

14

SEL say;

15

SEL Skin;

16

17	Define a function pointer (traditional C language processing method)

18	void (*SETSKINCOLOR_FUNC) (ID,SEL,nsstring*);

19

20	A function pointer that defines an IMP method (the recommended way in obj-c)

21st	IMP Say_func;

22

23	Define a class