如何更改UITableViewRowAction的标题

Question

I have a use case where I need to change the title of the UITableViewRowAction . For example, I have a restaurant cell, and when swipe right I show "bookmark(104)" where "bookmark" is the action and 104 means there have been 104 people bookmarked it. When click on it, I want it to change to "bookmark(105)" because obviously there's a new user(the current user himself) has bookmarked it. How do I do that? Tried the below code and it doesn't work.

let likeAction = UITableViewRowAction(style: UITableViewRowActionStyle.Default, title: "bookmark\n\(count)", handler:{(action, indexpath) -> Void in
        ....
        count++
        action.title = "bookmark\n\(count)"
    });

Answer 1

Here's a quick and dirty example.

Say you have a class Restaurant with a name and likes value:

class Restaurant {
    var name: String?
    var likes: Int = 0
}

You initialize a bunch of Restaurant objects, and put them in an array called dataSource . Your table view data source methods will look like this:

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return self.dataSource.count
}


override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    let cell = UITableViewCell(style: .Default, reuseIdentifier: "cell");
    cell.textLabel?.text = dataSource[indexPath.row].name

    return cell
}


// Override to support editing the table view.
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    // This can be empty if you're not deleting any rows from the table with your edit actions
}

override func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]? {

    // First, create a share action with the number of likes
    let shareAction = UITableViewRowAction(style: .Default, title: "\(self.dataSource[indexPath.row].likes)") { (action, indexPath) -> Void in

        // In your closure, increment the number of likes for the restaurant, and slide the cell back over
        self.dataSource[indexPath.row].likes++
        self.tableView.setEditing(false, animated: true)
    }

    return [shareAction] // return your array of edit actions for your cell.  In this case, we're only returning one action per row.
}

I'm not going to write a scrollable cell from scratch, since this question has a bunch of options you can use.

I was, however, intrigued by Andrew Carter's attempt to iterate through subviews to access the UIButton in the edit action directly. Here is my attempt:

First, create a reference to the UITableViewCell (or an array of cells), you wish to modify, for this example, I'll be using a single cell:

var cellRef: UITableViewCell?

// ...

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    let cell = UITableViewCell(style: .Default, reuseIdentifier: "cell");
    cell.textLabel?.text = dataSource[indexPath.row].name

    cellRef = cell;

    return cell
}

In your share action, iterate through the button's subviews. We're looking for the UITableViewCellDeleteConfirmationView and _UITableViewCellActionButton objects (private headers linked for reference).

let shareAction = UITableViewRowAction(style: .Default, title: "\(self.dataSource[indexPath.row].likes)") { (action, indexPath) -> Void in

    var deleteConfirmationView: UIView? // UITableViewCellDeleteConfirmationView

        if let subviews = self.cellRef?.subviews {
            for subview in subviews {
                if NSClassFromString("UITableViewCellDeleteConfirmationView") != nil {

                    if subview.isKindOfClass(NSClassFromString("UITableViewCellDeleteConfirmationView")!) {
                        deleteConfirmationView = subview
                        break
                    }
                }
            }
        }

    if let unwrappedDeleteView = deleteConfirmationView {
        if unwrappedDeleteView.respondsToSelector("_actionButtons") {
            let actionbuttons = unwrappedDeleteView.valueForKey("_actionButtons") as? [AnyObject]
            if let actionButton = actionbuttons?.first as? UIButton { // _UITableViewCellActionButton
                actionButton.setTitle("newText", forState: .Normal)
            }
        }

    }
}

Answer 2

This answer uses private API and it's NOT recommended to be used on the App Store. Apparently there is no way to change the title of the native UITableViewRowAction . You may have to implement your custom solution as suggested by others to achieve the result you want.

Here I'm traversing the subviews of UITableViewCell which contains private subviews and are subject to change so your code may crash on future iOS releases if Apple changes the view hierarchy. I found the header of UIButtonLabel here .

The current view hierarchy as per iOS 9.2 is

UITableViewCell
    UITableViewCellDeleteConfirmationView
        _UITableViewCellActionButton
            UIButtonLabel
                UIButton

Here is the code:

func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]? {
    let shareAction = UITableViewRowAction(style: .Default, title: "\(dataList[indexPath.row].likes)") { (action, indexPath) -> Void in
        self.dataList[indexPath.row].likes++
        let cell = tableView.cellForRowAtIndexPath(indexPath)
        let privateView = cell!.subviews[0].subviews[0].subviews[0]
        let privateButton = privateView.valueForKey("_button") as! UIButton
        privateButton.setTitle("\(self.dataList[indexPath.row].likes)", forState: .Normal)
    }

    return [shareAction]
} 

Answer 3

@JAL is totally right- you need to make your own sliding view to accomplish this, or be ok with reloading the cell and having it updated on the next slide out. Just for fun I tried to hack my way through the subviews and find the label and was able to find it, but what's funny is Apple has somehow blocked any changes being made to the text of that label. You can change it's background color / other properties but not the text!

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    @IBOutlet var tableView: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()

        tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")
    }

    func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        return 1
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 1
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
        return cell
    }

    func findRowActionLabelForCell(cell: UITableViewCell?) -> UILabel? {
        guard let cell = cell else {
            return nil
        }
        var label: UILabel? = nil

        for view in cell.subviews {
            label = findRowActionLabelForView(view)
            if label != nil {
                break
            }
        }

        return label
    }

    func findRowActionLabelForView(view: UIView) -> UILabel? {
        for subview in view.subviews {
            if let label = subview as? UILabel {
                return label
            } else {
                return findRowActionLabelForView(subview)
            }
        }

        return nil
    }

    func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]? {
        let action = UITableViewRowAction(style: .Default, title: "Test", handler: { (action, indexPath) -> Void in

            let cell = self.tableView.cellForRowAtIndexPath(indexPath)
            if let label = self.findRowActionLabelForCell(cell) {
                label.text = "New Value"
                label.backgroundColor = UIColor.blueColor()
            }

        })

        return [action]
    }

    func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {

    }

}