bflora2 bflora2 - 2 years ago 165
Swift Question

iOS: Hide or remove programmatically added subview when segmented control changes

I have a UITableView controlled by a UISegmentControl with 2 segments.

In segment 1, I am programmatically adding some views to the cell subview to add some visual elements to the cell.

When user switched to segment 2, I want these programmatically added views to go away. But they persist! I can't figure out how to get them to disappear when I switch to Segment 2.

Some code:

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! ProfilePokemonTableViewCell

var views: [String: UIView] = [:]
var piechart = Piechart2()

case 0:

let i:Int = indexPath.row
let curItem = self.pokemonAndIds[i]["data"] as! NSDictionary

let name = self.pokemonAndIds[indexPath.row]["data"]!!["name"] as! String

// MARK: - Add Piechart view programmaticaly
var views: [String: UIView] = [:]
var error = Piechart2.Slice()
error.value = 100 - CGFloat(aveIV)
error.color = UIColor.magentaColor()
error.text = "Error"
var win = Piechart2.Slice()
win.value = CGFloat(aveIV)
win.color = UIColor(netHex:0x6cedb8)
win.text = "Winner"

piechart.title = "42"
piechart.activeSlice = 1
piechart.radius.inner = 12
piechart.radius.outer = 23
piechart.layer.borderWidth = 0
piechart.slices = [error, win]
piechart.subtitle = ""
piechart.translatesAutoresizingMaskIntoConstraints = false
views["piechart"] = piechart
cell.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:[piechart(==66)]-10-|", options: [], metrics: nil, views: views))
cell.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-5-[piechart(==66)]", options: [], metrics: nil, views: views))

case 1:
cell.nameLabel.text = self.userFriendList["data"]![indexPath.row]["name"] as! String


In this code above, the Piechart element appears when I switch to the second segment. I can't figure out how to hide it, remove it from the view, delete it, or whatever is needed to make it not appear in the second segment.

Answer Source

As you are reinstantiating the PiChart object in the cellForRowAtIndexPath method, you no longer have a reference to the PiChart that you can see on your screen. Saying that, the cell should be re-created at this point but I have known that not to happen. Although this is not an ideal solution by any means it is worth trying just to confirm suspicions.

As much as I hate climbing into the view hierarchy like this, if you have lost the reference to the object it can sometimes be the better approach.

for subview in cell.contentView.subviews {
    if let pichart = subview as? Piechart2 {
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