respondsToSelector判断是否实现了某方法

Tester.h

 

#import <Foundation/Foundation.h>


@interface Tester : NSObject {

}

-(void) test:(NSString*) msg;

-(void) notImp;

@end

Tester.m

#import "Tester.h"

@implementation Tester

-(void) test:(NSString*) msg
{
NSLog(@"%@", msg);
}

@end

注意：没有实现notImp方法

 

main.m

 

#import <Foundation/Foundation.h>
#import "Tester.h"

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

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

id tester = [[Tester alloc] init];//注意，这里使用id

SEL testSelector = @selector(test:);
SEL notImpSelector = @selector(notImp:);

if([tester respondsToSelector:testSelector])
{
//tester.m中实现了test方法
[tester test:@"invoke test method"];
}
if([tester respondsToSelector:notImpSelector])
{
//test.m中没有实现此主就去
[tester notImp];
}


[pool drain];
return0;
}