如何获取汽车对应的按钮

NSArray *className =@[@"飞机",@"汽车",@"手机",@"电脑",@"电视"];

    for (int i=0; i<5; i++) {

        CGRect btRect;

        CGRect imageRect;

        CGRect titleRect;

        btRect = CGRectMake(i*SCREEN_WIDTH/5, 75, SCREEN_WIDTH/5, 50);

        imageRect =CGRectMake((SCREEN_WIDTH/5-30)/2, 0, 30, 30);

        titleRect =CGRectMake(0, 32, SCREEN_WIDTH/5, 18);

        ClassButton *bt_class =[[ClassButton alloc]initWithFrame:btRect imageFrame:imageRect titleFrame:titleRect];

        NSString *image =[NSString stringWithFormat:@"home_class%d.png",i+1];

        NSString *title =[className objectAtIndex:i];

        [bt_class setImage:[UIImage imageNamed:image] forState:UIControlStateNormal];

        [bt_class setTitle:title forState:UIControlStateNormal];

        [bt_class setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];

        bt_class.titleLabel.font =[UIFont systemFontOfSize:12];

        //飞机

        for (int i=0; i<className.count; i++) {

            NSString *bt=[className objectAtIndex:0];

        }

        [bt_class addTarget:self action:@selector(loginAction3) forControlEvents:UIControlEventTouchUpInside];