-(void)setInvok:(id)target sel:(SEL)sel key:(id)key

{

    if(!target) return;

    NSMethodSignature *sig=[target methodSignatureForSelector:sel];

    NSInvocation *invo=[NSInvocation invocationWithMethodSignature:sig];

    [invo setTarget:target];

    [invo setSelector:sel];

    NSDictionary *dict = [self currentStyleDict];

    [dict setValue:invo forKey:key];//以key的形式保存invo

}

-(NSInvocation*)selectInvok:(NSString *)key style:(PALiveStyle)style

{

    NSDictionary *dict = [self getStyleDict:style];

    return [dict valueForKey:key];

}

//常规写法

switch ( oper ){

    case ADD:

        result = add( oper1, oper2 );

        break;

    case SUB:

        result = sub( oper1, oper2 );

        break;

    case MUL:

        result = mul( oper1, oper2 );

        break;

    case DIV:

        result = div( oper1, oper2 );

        break;

    ...

}

//使用转移表之后的写法

double add( double, double );

double sub( double, double );

double mul( double, double );

double div( double, double );

...

double (*oper_func[])( double, double ) = {

    add, sub, mul, div, ...

};

//下面的语句替换前面整条switch语句

result = oper_func[ oper ]( op1, op2 );

- (bool)startPlayingStream:(NSString *)streamID inView:(UIView*)view

{

//    NSInvocation *invo=[[MessageInvok shareInvok] selectInvok:@"start_playing_stream" style:PALiveStyleNormal];

//    if(invo)

//    {

////        [data retain];

//        [invo setArgument:&streamID atIndex:2];  //设置参数

//        [invo setArgument:&view atIndex:3];  //设置参数

//        [invo invoke];   //调用

//    }

//    [self invokeMethod:@"start_playing_stream" style:PALiveStyleNormal,streamID,view];

    [self invokeMethod:@"start_playing_stream" style:PALiveStyleNormal arg:streamID,view, nil];

    return true;

}

- (bool)stopPlayingStream:(NSString *)streamID

{

    return true;

}

-(NSInvocation *)invokeMethod:(NSString *)method style:(PALiveStyle)style arg:(id)arg, ...

{

    NSMutableArray *arrayList = [NSMutableArray array];

    id eachItem;

    va_list argumentList;

    if (arg)

    {

        [arrayList addObject: arg];

        va_start(argumentList, arg);

        while((eachItem = va_arg(argumentList, id)))

        {

            [arrayList addObject: eachItem];

        }

        va_end(argumentList);

    }

    NSInvocation *invo=[[MessageInvok shareInvok] selectInvok:@"start_playing_stream" style:style];

    if(invo)

    {

        for (NSUInteger i =; i<arrayList.count; i++) {

            NSInteger idx = i+;

            id data = arrayList[i];

            [invo setArgument:&data atIndex:idx];

        }

        [invo invoke];   //调用

    }

    return invo;

}