如何使用 iOS11+ 拖放更改正在拖动的单元格的背景?

问题描述

我正在尝试在 UICollectionView 中实现新的拖放方法，但不知道如何从被拖动的单元格中删除背景.

I'm trying to implement the new drag-n-drop methods in UICollectionView and can't figure out how to remove the background from a cell that's being dragged.

问题截图如下:

这是我正在尝试的代码:

Here's the code I'm trying:

func collectionView(_ collectionView: UICollectionView, dragPreviewParametersForItemAt indexPath: IndexPath) -> UIDragPreviewParameters? {
    let parameters = UIDragPreviewParameters()
    parameters.backgroundColor = .clear
    return parameters
}

问题是，它真的不起作用.背景仍然可见.我正在考虑使用 visiblePath: UIBezierPath，但我认为它不会很好地处理文本.

Problem is, it doesn't really work. The background is still visible. I'm thinking of using visiblePath: UIBezierPath, but I don't think it's going to play nice with text.

有没有办法完全去除这个背景?

Is there a way to just remove this background completely?

推荐答案

我不确定有没有不使用 UIBezierPath 的方法.

I'm not sure there is a way to do so without using UIBezierPath.

这是我为类似的东西所做的一个例子:

Here is an example of what I did for something similar:

final class CustomCell: UITableViewCell {
    @IBOutlet weak var mySuperLabel: UILabel!
    @IBOutlet weak var whiteSubview: UIView! // I have added a cornerRadius of 12.0 in the XIB
}

那么，委托方法:

func tableView(_ tableView: UITableView, dragPreviewParametersForRowAt indexPath: IndexPath) -> UIDragPreviewParameters? {
    let cell = tableView.cellForRow(at: indexPath) as! CustomCell
    let previewParameters = UIDragPreviewParameters()
    let path = UIBezierPath(roundedRect: cell.whiteSubview.frame, cornerRadius: 12.0)
    previewParameters.visiblePath = path
    previewParameters.backgroundColor = .clear
    return previewParameters
}

结果:

这篇关于如何使用 iOS11+ 拖放更改正在拖动的单元格的背景?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！