ios - 为何按钮点击无反应？

/*这段代码功能是添加按钮，视图上移，但是发现在上移的视图里，添加的按钮不响应，这是为什么呢？*/


    -(void)showView
    {
        UIView *addView = [[UIView alloc] initWithFrame:CGRectMake(0, SCREENSIZE.height,SCREENSIZE.width, 80)];
        [addView setBackgroundColor:[UIColor whiteColor]];
        UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(10, 10, 80, 40)];
        [btn setTitle:@"相册" forState:UIControlStateNormal];
        [btn setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
        [btn addTarget:self action:@selector(openPhoto1) forControlEvents:UIControlEventTouchUpInside];
        [addView addSubview:btn];
        [self.view addSubview:addView];
        
        //计算控制器的view需要平移的距离
        CGFloat moveY=0;
        if (_bShowAddView==false)
            moveY  = -80;
        else
            moveY=0;
        _bShowAddView=!_bShowAddView;
        //
        //    // 4,执行动画
        [UIView animateWithDuration:0.5 animations:^{
            self.view.transform = CGAffineTransformMakeTranslation(0, moveY);
        }];
    }
    -(void)openPhoto1
    {
        NSLog(@"test");
    }