@interface TestObject : NSObject-(void)printFirstName:(NSString*)firstName thenSecondName:(NSString*)secondName;-(void)printName:(NSString*)name;-(int)addLeft:(int)left withRight:(int)right;@end

@implementation TestObject-(SEL)oriSelector:(SEL)aSelector{    NSString* v2String=NSStringFromSelector(aSelector);    NSString* oriString=[v2String stringByReplacingCharactersInRange:NSMakeRange(0, 2) withString:@""];    return NSSelectorFromString(oriString);}-(void)changeInvocation:(NSInvocation*)invocation{    SEL aSelector=[invocation selector];       [invocation setSelector:[self oriSelector:aSelector]];}-(void)v2Method:(NSInvocation*)invocation{    NSLog(@"hello");    [self changeInvocation:invocation];    [invocation invokeWithTarget:self];    NSLog(@"goodbye");}-(void)v3Method:(NSInvocation*)invocation{    NSLog(@"fuck");    [self changeInvocation:invocation];    [invocation invokeWithTarget:self];}-(NSMethodSignature*)methodSignatureForSelector:(SEL)aSelector{    NSString* vString=NSStringFromSelector(aSelector);    NSString* oriString=[vString stringByReplacingCharactersInRange:NSMakeRange(0, 2) withString:@""];    NSMethodSignature*  signature=[super methodSignatureForSelector:NSSelectorFromString(oriString)];    return signature;}-(void)forwardInvocation:(NSInvocation *)anInvocation{    SEL aSelector=[anInvocation selector];    NSString* aSelectorString=NSStringFromSelector(aSelector);    if([aSelectorString hasPrefix:@"v2"])       [self v2Method:anInvocation];    else if([aSelectorString hasPrefix:@"v3"])        [self v3Method:anInvocation];}-(void)printFirstName:(NSString *)firstName thenSecondName:(NSString *)secondName{    NSLog(@"%@ %@",firstName,secondName);}-(void)printName:(NSString*)name{    NSLog(@"%@",name);}-(int)addLeft:(int)left withRight:(int)right{    int value=left+right;    NSLog(@"%d add %d is %d",left,right,value);    return value;}@end

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{      TestObject* t=[[TestObject alloc]init];    [t printFirstName:@"your" thenSecondName:@"sister"];        [t v2printFirstName:@"your" thenSecondName:@"sister"];    [t v3printName:@"your sister"];    int a=(int)[t v2addLeft:2 withRight:2];    NSLog(@"%d",a);    //.....}