Android开发：点击电台列表单元格显示播放图标并隐藏原图标

Hey there! Let's fix this play icon toggle issue for your radio app—super common requirement, and totally solvable with a few key steps.

First, let's recap your core need to make sure we're aligned:

点击电台列表的某一单元格时，在该单元格内显示播放图标，同时隐藏之前显示的播放图标。例如，点击“电台1”开始播放后，在其右侧显示播放图标；当点击另一单元格时，需隐藏原播放图标，在新选中的单元格中显示该图标。

You also shared this unfinished code snippet:

// MARK: - QUERY STATIONS ---------------------------------------------------------------
void queryStations(String...

Let's build out the solution around this, including handling table view cell reuse (a critical detail to avoid weird icon glitches):

1. Track the Currently Playing Station #

First, add a property to your view controller to keep track of which cell is currently displaying the play icon. If you're using UITableView, we'll store the IndexPath of the active cell:

// Add this to your ViewController class
private var currentPlayingIndexPath: IndexPath?

2. Handle Cell Selection Logic #

In your table view's didSelectRowAt method, we'll toggle the icons between the old and new selected cells:

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    // Step 1: Hide the play icon from the previously active cell
    if let previousPath = currentPlayingIndexPath {
        if let previousCell = tableView.cellForRow(at: previousPath) as? YourStationCell {
            previousCell.playIconImageView.isHidden = true
        }
    }
    
    // Step 2: Show the play icon on the newly selected cell
    if let currentCell = tableView.cellForRow(at: indexPath) as? YourStationCell {
        currentCell.playIconImageView.isHidden = false
    }
    
    // Step 3: Update our tracker to the new active cell
    currentPlayingIndexPath = indexPath
    
    // Add your actual radio playback logic here (e.g., using your queryStations data)
    startPlayingStation(at: indexPath)
}

Note: Replace YourStationCell with your actual custom cell class name, and playIconImageView with the name of your play icon UI element in the cell.

3. Fix Cell Reuse Glitches #

Table views reuse cells, so we need to ensure the play icon displays correctly when cells are recycled. Update your cellForRowAt method:

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "YourStationCellID", for: indexPath) as! YourStationCell
    
    // Configure your cell's content (using data from queryStations)
    let station = yourStationsDataSource[indexPath.row]
    cell.stationNameLabel.text = station.name
    
    // Set play icon visibility based on the current active cell
    cell.playIconImageView.isHidden = (currentPlayingIndexPath != indexPath)
    
    return cell
}

4. Handle External Playback State Changes #

If your radio can stop playing outside of cell taps (e.g., end of stream, user taps pause), add logic to update the icon state:

func handlePlaybackStopped() {
    if let activePath = currentPlayingIndexPath {
        // Hide the icon from the active cell
        if let activeCell = tableView.cellForRow(at: activePath) as? YourStationCell {
            activeCell.playIconImageView.isHidden = true
        }
        // Reset the active cell tracker
        currentPlayingIndexPath = nil
    }
}

内容的提问来源于stack exchange，提问作者Frank Eno