在Swift中点击时展开单元格 [英] Expand cell when tapped in Swift

问题描述

我一直在尝试在我的应用中实现一项功能，以便当用户点击我的表格视图中的单元格时，单元格向下展开以显示注释。我在Objective-C中找到了很多这样的例子，但我还没有找到任何Swift。

I have been trying to implement a feature in my app so that when a user taps a cell in my table view, the cell expands downwards to reveal notes. I have found plenty of examples of this in Objective-C but I am yet to find any for Swift.

这个例子看起来很完美：手册表格单元格 - 如何动态扩展/收缩uitableviewcell？

This example seems perfect: Accordion table cell - How to dynamically expand/contract uitableviewcell?

我试图将其翻译成Swift：

I had an attempt at translating it to Swift:

var selectedRowIndex = NSIndexPath()
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    selectedRowIndex = indexPath
    tableView.beginUpdates()
    tableView.endUpdates()
}

override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    if selectedRowIndex == selectedRowIndex.row && indexPath.row == selectedRowIndex.row {
        return 100
    }
    return 70
}

然而，这似乎让应用程序崩溃。

However this just seems to crash the app.

有什么想法吗？

编辑：

这是我的cellForRowAtIndexPath代码：

Here is my cellForRowAtIndexPath code:

    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    var cell:CustomTransactionTableViewCell = self.tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as CustomTransactionTableViewCell

    cell.selectionStyle = UITableViewCellSelectionStyle.None

    if tableView == self.searchDisplayController?.searchResultsTableView {
        cell.paymentNameLabel.text = (searchResults.objectAtIndex(indexPath.row)) as? String
        //println(searchResults.objectAtIndex(indexPath.row))
        var indexValue = names.indexOfObject(searchResults.objectAtIndex(indexPath.row))
        cell.costLabel.text = (values.objectAtIndex(indexValue)) as? String
        cell.dateLabel.text = (dates.objectAtIndex(indexValue)) as? String

        if images.objectAtIndex(indexValue) as NSObject == 0 {
            cell.paymentArrowImage.hidden = false
            cell.creditArrowImage.hidden = true
        } else if images.objectAtIndex(indexValue) as NSObject == 1 {
            cell.creditArrowImage.hidden = false
            cell.paymentArrowImage.hidden = true
        }
    } else {
        cell.paymentNameLabel.text = (names.objectAtIndex(indexPath.row)) as? String
        cell.costLabel.text = (values.objectAtIndex(indexPath.row)) as? String
        cell.dateLabel.text = (dates.objectAtIndex(indexPath.row)) as? String

        if images.objectAtIndex(indexPath.row) as NSObject == 0 {
            cell.paymentArrowImage.hidden = false
            cell.creditArrowImage.hidden = true
        } else if images.objectAtIndex(indexPath.row) as NSObject == 1 {
            cell.creditArrowImage.hidden = false
            cell.paymentArrowImage.hidden = true
        }
    }
    return cell
}

以下是插座设置：

推荐答案

if语句中的第一个比较永远不会为真，因为您将indexPath与整数进行比较。您还应该使用不能在表中的行值初始化selectedRowIndex变量，例如-1，因此在表首次加载时不会展开任何内容。

The first comparison in your if statement can never be true because you're comparing an indexPath to an integer. You should also initialize the selectedRowIndex variable with a row value that can't be in the table, like -1, so nothing will be expanded when the table first loads.

var selectedRowIndex: NSIndexPath = NSIndexPath(forRow: -1, inSection: 0)

override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    if indexPath.row == selectedRowIndex.row {
        return 100
    }
    return 70
}

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