以发送sendMessage:带参方法为例

1、动态方法解析

 + (BOOL)resolveInstanceMethod:(SEL)sel{

    //动态方法解析

    NSString*methodName =NSStringFromSelector(sel);

    if([methodNameisEqualToString:@"sendMessage:"]) {

        class_addMethod(self, sel, (IMP)sendMessage,"v@:@");

    }

    return NO;

}

2、快速转发

 + (BOOL)resolveInstanceMethod:(SEL)sel

{

    return NO;

}

backUpPerson是备份类方法

- (id)forwardingTargetForSelector:(SEL)aSelector

{

    //快速查找

        NSString*methodName =NSStringFromSelector(aSelector);

        if([methodName isEqualToString:@"sendMessage:"]) {

            return [backUpPerson new];

        }

    return [super forwardingTargetForSelector:aSelector];

}

3、慢速转发分两步 

    a、方法签名  b、消息转发

+ (BOOL)resolveInstanceMethod:(SEL)sel

{

return NO;

}

- (id)forwardingTargetForSelector:(SEL)aSelector

{

        [super forwardingTargetForSelector:aSelector];

}

//方法签名

- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector

{

    NSString*methodName =NSStringFromSelector(aSelector);

    if([methodName isEqualToString:@"sendMessage:"]) {

        return [NSMethodSignature signatureWithObjCTypes:"v@:@"];

    }

    return [super methodSignatureForSelector:aSelector];

}

//消息转发

- (void)forwardInvocation:(NSInvocation*)anInvocation

{

    SELsel = [anInvocation selector];

    backUpPerson *tempObj = [backUpPerson new];

    if([tempObj respondsToSelector:sel]) {

        [anInvocation invokeWithTarget:tempObj];

    }else{

        [super forwardInvocation:anInvocation];

    }

}

三者都找不到方法时，最后调用

- (void)doesNotRecognizeSelector:(SEL)aSelector

{

NSLog(@"找不到方法");

}