故事板父子关系不代表“超级视图"返回的内容 [英] Storyboard parent-child relationship not representing what is returned by "superview"

问题描述

Collection View Cell 子类化如下:

The Collection View Cell is subclassed in the following way:

我在集合视图中有这个布局.在创建每个按钮时，我调用以下代码:

I have this layout in a collection view. On each button when it is created, I call the following code:

    [cell.imageButton addTarget:self action:@selector(galleryImageButtonClicked:event:) forControlEvents:UIControlEventTouchUpOutside];

这称为:

    -(void)galleryImageButtonClicked:(id)sender event:(id)event
{
    if ([sender isKindOfClass:[UIButton class]])
    {
        NSLog(@"Yay, it's a UIButton.");
        SCCollectionViewCell* parentCellOfThisButton = (SCCollectionViewCell*)[sender superview];
        if ([parentCellOfThisButton isKindOfClass:[SCCollectionViewCell class]])
        {
            UICollectionView *parentCollectionView = (UICollectionView* )[parentCellOfThisButton superview];
        if ([parentCollectionView isKindOfClass:[UICollectionView class]])
        {
            NSIndexPath* indexPathOfCell = [parentCollectionView indexPathForCell:parentCellOfThisButton];



        } else {
            NSLog(@"Not a UIcollectionClass");
        }
    } else {
        NSLog(@"ERROR! 15268679");
    }
}
}

这样就失败了:

        if ([parentCellOfThisButton isKindOfClass:[SCCollectionViewCell class]])

有人知道为什么吗?

推荐答案

为了工作，代码需要知道按钮在单元格视图层次结构中的位置.编写一个更一般地查找按钮单元格的方法可能会更好，如下所示:

To work, the code needs to know where in the cell's view hierarchy the button sits. It might be better to write a method that finds the button's cell more generally, like this:

- (UICollectionViewCell *)cellContainingSubview:(UIView *)view {

    while (view && ![view isKindOfClass:[UICollectionViewCell self]]) {
        view = [view superview];
    }
    return view;
}

然后在你的按钮方法中，没有必要检查发送者是否是一个按钮(只有按钮调用这个选择器，对吧?).像这样获取包含单元格:

Then in your button method, there's no need to check if the sender is a button (only the buttons invoke this selector, right?). Get the containing cell like this:

SCCollectionViewCell* parentCellOfThisButton = (SCCollectionViewCell*)[self cellContainingSubview:sender];

请注意，只有当您知道只有 SCCollectionViewCells 包含使用此方法的按钮时，才能进行转换.

Note that the cast is only okay if you know that only SCCollectionViewCells contain the buttons that use this method.

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