How can I use indexPathForSelectedRow in CollectionView?
CollectionView/TableView:
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("levelCell", forIndexPath: indexPath) as! CollectionViewCell
guard levelListen != nil else {
return cell
}
let levelListe = levelListen[indexPath.row]
cell.levelLabel?.text = levelListe.name
return cell
}
TableView - prepareForSegue (work):
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "zumLevel" {
let dstCtl = segue.destinationViewController as! InLevelViewController
let indexPath = tableView.indexPathForSelectedRow!
dstCtl.levelList = levelListen[indexPath.row]
}
}
CollectionView - prepareForSegue (not work):
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "zumLevel" {
let dstCtl = segue.destinationViewController as! InLevelViewController
// like TableView?
let indexPath = collectionView.indexPathsForSelectedItems()!
dstCtl.levelList = levelListen[indexPath.row] // <--- .row doesn't work, should I use .count ?
}
}
When I try .count it says: "unexpectedly found nil while unwrapping an Optional value"
collectionView.indexPathsForSelectedItems() returns multiple IndexPath's because you can select multiple cells. This function returns an array of IndexPaths, e.g [NSIndexPath].
It should work if you'd do something like:
let indexPath = collectionView.indexPathsForSelectedItems()
if let lastRowSelected = indexPath?.last?.row {
dstCtl.levelList = levelListen[lastRowSelected]
}
Related
I'm trying to pass the indexPath of a cell tapped in a UICollectionView to another view controller. I can't seem to get the indexPath of what was selected and segue it to the next view controller
I get this error: "Could not cast value of type Post to PostCell"
View Controller #1:
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let post = posts[indexPath.row]
if let cell = collectionView.dequeueReusableCellWithReuseIdentifier("PostCell", forIndexPath: indexPath) as? PostCell {
cell.configureCell(post)
}
return cell
}
}
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
let selectedPost: Post!
selectedPost = posts[indexPath.row]
performSegueWithIdentifier("PostDetailVC", sender: selectedPost)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "PostDetailVC" {
//Error here: Could not cast value of Post to PostCell
if let selectedIndex = self.collection.indexPathForCell(sender as! PostCell){
print(selectedIndex)
}
if let detailsVC = segue.destinationViewController as? PostDetailVC {
if let selectedPost = sender as? Post {
print(selectedIndex)
detailsVC.post = selectedPost
detailsVC.myId = self.myId!
detailsVC.indexNum = selectedIndex
}
}
}
}
View Controller #2:
var indexNum: NSIndexPath!
override func viewDidLoad() {
super.viewDidLoad()
print(indexNum)
}
You are passing a Post instance which doesn't match the expected PostCell instance.
I recommend to pass the index path
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
performSegueWithIdentifier("PostDetailVC", sender: indexPath)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "PostDetailVC" {
guard let selectedIndexPath = sender as? NSIndexPath,
detailsVC = segue.destinationViewController as? PostDetailVC else { return }
print(selectedIndexPath)
let selectedPost = posts[selectedIndexPath.row]
detailsVC.post = selectedPost
detailsVC.myId = self.myId!
detailsVC.indexNum = selectedIndexPath
}
}
You are passing a Post and not a PostCell as sender. You don't need that anyway, as the collectionView keeps track of selected items.
Try this:
if let selectedIndex = self.collection.indexPathsForSelectedItems()?.first {
print(selectedIndex)
}
It's because you are giving argument which has type of Post and you are trying to cast it as PostCell. Which will not work.
I'm getting fatal error: unexpectedly found nil while unwrapping an Optional value when I segue from the cell.
Here's the code:
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if indexPath.section == 1 {
let listIngredients = recipeItem.ingredients[indexPath.row]
selectedIngredient = listIngredients.ingredient
}
tableView.deselectRowAtIndexPath(indexPath, animated: false)
performSegueWithIdentifier("showIngredientInRecipe", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "showIngredientInRecipe" {
let svc = segue.destinationViewController as! UINavigationController
let destination = svc.topViewController as! IngredientDetailViewController
destination.ingredientItem = selectedIngredient
print("selectedIngredient \n \(selectedIngredient)")
}
}
Here's what I get from the debugger:
selectedIngredient
nil
selectedIngredient
Optional(Ingredient {
name = Rye Whiskey;
inStock = 1;
type = IngredientType {
name = Spirit;
};
})
fatal error: unexpectedly found nil while unwrapping an Optional value
As you can see, the selectedIngredient prints twice. First as nil, second time with the expected content. If i replace destination.ingredientItem = selectedIngredient with destination.ingredientItem = recipeItem.ingredients[0].ingredient the segue runs fine with no errors.
You're checking if indexPath's section is 1 and if it's not it will still perform segue. Make sure your selectable cells are in section 1 (or section 0?) and move your performSegueWithIdentifier("showIngredientInRecipe", sender: self) call to if statement to make it more safe.
Fixed:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "showIngredientInRecipe" {
if let selectedIndexPath = self.tableView.indexPathForSelectedRow {
if selectedIndexPath.section == 1 {
let listIngredients = recipeItem.ingredients[selectedIndexPath.row]
selectedIngredient = listIngredients.ingredient
let svc = segue.destinationViewController as! UINavigationController
let destination = svc.topViewController as! IngredientDetailViewController
destination.ingredientItem = selectedIngredient
print("selectedIngredient \n \(selectedIngredient)")
}
}
}
}
Your code is error prone because you can perform segue regardless of
the section
A better way to get the selected item, is to call indexPathForSelectedRow() method inside of the delegate
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if indexPath.section == 1 {
performSegueWithIdentifier("showIngredientInRecipe", sender: self)
}
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "showIngredientInRecipe" {
//get selected item
let indexPath = self.tableView.indexPathForSelectedRow() {
let selectedIngredient = recipeItem.ingredients[indexPath.row]
print("selectedIngredient \n \(selectedIngredient)")
//segue
let svc = segue.destinationViewController as! UINavigationController
let destination = svc.topViewController as! IngredientDetailViewController
destination.ingredientItem = selectedIngredient
}
}
}
When I segue my UIImageView from my NewsTableViewController.swift, the image does not appear in my NewsDetailTableViewController.swift.
Here is an image of my simulator:
Here is an image of my Main.storyboard:
Here is my prepareForSegue() method code:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?){
if segue.identifier == "showDetail" {
if let indexPath = tableView.indexPathForSelectedRow {
let destinationController = segue.destinationViewController as! NewsDetailTableViewController
destinationController.item = items[indexPath.row]
let newsImage = UIImageView(image: UIImage(named: detailImages[indexPath.row]))
destinationController.image = newsImage
}
}
}
It is also worth mentioning that my image in my NewsTableViewController.swift is set to 0x0, and in my NewsDetailTableViewController.swift, it is set to 600x216. I don't know if this would matter or not. If you desire any code, please do feel free to ask.
FYI, I use Swift.
In prepareForSegue the IBOutlets of your destinationController have not been initialized yet. Just pass detailImages to another array property on NewsDetailTableViewController. Change your prepareForSegue to:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?){
if segue.identifier == "showDetail" {
if let indexPath = tableView.indexPathForSelectedRow {
let destinationController = segue.destinationViewController as! NewsDetailTableViewController
destinationController.item = items[indexPath.row]
destinationController.imageNames = detailImages
}
}
}
Then in NewsTableViewController add the following code:
var imageNames:[String]?
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
//replace with whatever identifier you're using
var cell:UITableViewCell = self.tableView.dequeueReusableCellWithIdentifier("Cell") as UITableViewCell
cell.imageView?.image = self.imageNames[indexPath.row]?
return cell
}
I need to add a value to the selected row than in prepareForSegue that it does its action.But my prepareForSegue is doing the action before it.When i try to place the "performSegueWithIdentifier" it crashes,also i have added the id to the segue idenfifier in the storyboard.Im working with sqlite.
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
selectedRow = indexPath.row
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if(segue.identifier == "editSegue")
{
let viewController : WorkoutView = segue.destinationViewController as! WorkoutView
viewController.workoutInfoData = marrStudentData.objectAtIndex(selectedRow) as! WorkoutInfo
navigationItem.title = ""
}
}
You can fetch the selected indexPaths from tableView in your prepare for segue
func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if(segue.identifier == "editSegue")
{
if let indexPath = tableView.indexPathForSelectedRow{
let viewController : WorkoutView = segue.destinationViewController as! WorkoutView
viewController.workoutInfoData = marrStudentData.objectAtIndex(indexPath.row) as! WorkoutInfo
navigationItem.title = ""
}
}
}
I'm trying to get the name of the selected row in the custom cell. How I can do that in Swift?
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
var selectedCell = CustomCell()
selectedCell = tableView(tbl, cellForRowAtIndexPath: <#NSIndexPath#>)
if(segue.identifier == "next") {
var next = (segue.destinationViewController as! EngineViewController)
next.titleSub = selectedCell.cell.lblBrand.text
}
}
I believe if you are just selecting a cell, the cell should be the sender. Try this
if let selectedCell = sender as? CustomCell {
if(segue.identifier == "next") {
var next = (segue.destinationViewController as! EngineViewController)
next.titleSub = selectedCell.cell.lblBrand.text
}
}
You could attempt to override didSelectRowAtIndexPath to get your cell.
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let cell = tableView.dequeueReusableCellWithIdentifier("CellIdentifier", forIndexPath: indexPath) as! CustomCell
cell.yourLabel.textYouWant
let yourViewController = storyboard?.instantiateViewControllerWithIdentifier("ViewController") as! ViewController
navigationController?.pushViewController(yourViewController, animated: true)
}