不能通过iVar / property访问UIButton

Question

我以编程方式创建了一个UIButton，并将其放入一个属性中:

    UIButton *button = _homeButton; 
    UIImage *image = [UIImage imageNamed:@"homeButton"];
    button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button addTarget:self action:@selector(checkHide:) forControlEvents:UIControlEventTouchUpInside];
    [button setBackgroundImage:image forState:UIControlStateNormal];
    button.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, image.size.width, image.size.height);
    [[self superview] insertSubview:button belowSubview:self];

现在，让我们检查选择器:
由于某些原因，这可以工作:

- (void)checkHide:(UIButton *)sender {
        [sender removeFromSuperview];
}

但这不是:

- (void)checkHide:(UIButton *)sender {
    [_homeButton removeFromSuperview];
}  

为什么我需要后一种解决方案?因为我想通过点击另一个按钮来移除这个按钮。因此，我无法从中获得任何发送者。尽管如此，checkHide方法中的代码仍在执行，在这种情况下，我不能使用iVar或属性操作按钮。任何想法吗?

Answer 1

您没有正确使用指针。首先，将"按钮"指针设置为_homeButton。在第三行，你将"button"指针设置为一个新的UIButton。
基本上,这:

button = [UIButton buttonWithType:UIButtonTypeCustom];

抵消了

UIButton *button = _homeButton;

Answer 2

您没有在代码中分配_homeButton。试试这个:

UIImage *image = [UIImage imageNamed:@"homeButton"];
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button addTarget:self action:@selector(checkHide:) forControlEvents:UIControlEventTouchUpInside];
[button setBackgroundImage:image forState:UIControlStateNormal];
button.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, image.size.width, image.size.height);
[[self superview] insertSubview:button belowSubview:self];
_homeButton = button;