I've done many apps with simple tableviews and I'm comfortable with them. I've never used a custom tableViewCell until today. I started with a really custom cell with two labels and that renders normally. I can populate my two labels with my data, no problem. I thought it would be equally easy to add the standard checkmark using:
cell.accessoryType = .Checkmark
My cells render the labels properly but I don't get a checkmark. Is there something extra I need to do to render an accessory type with a custom tableViewCell?
edit: I tried to not just use a default accessoryType. I created an image, an imageview, and set cell.accessoryView to that view and that doesn't display either. Obviously I'm missing something in my custom cell
try this code:
func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
// your cell coding here and set cell accessory view checkmark
cell.accessoryType = IUTableViewCellAccessoryType.Checkmark
}
UITableViewCell consist of 2 subviews:
contentView
accessoryView
When you are creating your own custom cell (that extends UITableViewCell) add your views to contentView. (See docs)
It is possible that you have added your views directly to UITableViewCell and in this case you are drawing your subviews on top of accessoryView.
Related
I'm using the typical method of dynamically sizing table view cells that contain text views in them:
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 44
This works just fine for the cells I actually instantiate and use, but it has a strange side effect: the empty cells that the table view shows below instantiated cells end up resizing their height alongside whichever custom cell I'm currently editing.
So when I input three, four, or more lines of text into a newly added custom cell...
...all the other prototype-based custom cells already filled in the
table remain unchanged
...the custom cell being edited resizes dynamically as intended
...but all the "ghost" cells below the last custom cell in the table
view end up dynamically expanding alongside the custom cell that's
being edited
My first thought was that it must have something to do with how I dequeue cells, and specifically what I return when dequeueing doesn't happen:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let myCell = tableView.dequeueReusableCell(withIdentifier: "myCustomCell", for: indexPath) as? CustomCell {
return myCell
} else {
return CustomCell()
}
}
But I tried returning both my custom cell and just UITableViewCell() in the else block and the result is the same.
Does anyone know why this could possibly be happening and/or how to get around it?
In my tableview, every cell will be different and determined by a JSON response from server. And there will be infinite possibilities. So defining a prototype for each type of cell is not possible.
For example, one cell will have labels and buttons, another cell have images and buttons in different orders.
How to achieve this dynamic structure in tableview cells?
Currently what I am doing is: adding views as subview in cellForRowAtIndexPath but scrolling is very laggy this way.
How to achieve this without affecting performance this much
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell") as! MyCell
for myview in data[indexPath.row].myviews{
cell.addSubview(myview)
}
return cell
}
If you're using a table view then your content is going to scroll vertically, right?
There is a physical limit to the amount of UI that you can put horizontally. Limited by the screen size.
So I'm guessing your UI parts are being laid out vertically in the cell?
So instead of laying out a button, label, image, another button, and a text field vertically in a cell...
Create a cell type called ButtonCell, LabelCell, ImageCell, MultiLineLabelCell, TextFieldCell, etc...
So now, instead of creating one cell with all these elements added. You instead create multiple cells each containing one type of UI. Now you can dequeue your cells in any particular order (driven by your JSON) and won't lose the performance.
The only solution I see is to have empty cell and add/remove subviews as needed. But you should add new subviews to a cell only if you did not add them before.
For example:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell") as! MyCell
if cell.contentView.viewWithTag(1) == nil {
let label = UILabel()
label.tag = 1
cell.contentView.addSubview(label)
}
let label = cell.contentView.viewWithTag(1)
// label config there
return cell
}
Also don't forget to add subviews to cell's contentView not to cell itself.
I'm new to iOS and trying to rewrite an app from android.
What I do in Android - I have a layout - same as nib in xcode
And then I inflate this view as many times I want - same as ListView (TableView's android analog) is working
I need to do this on iOS :
which means having some container like Android's horisontal LinearLayout where I can add nib's with their class - like UITableViewCell and fill data.
When I asked one person who is iOS developer, he told me that it is almost impossible to do due to compexity and lack of android-like ViewGroups and that it's better to do in a WebView than natively.
So please, tell me , is there a solution - to inflate as many views as needed from a nib into container-views one under another ? Please answer in Swift, I don't know Obj-c at all
Yes you can do it by registering your tableView with Xib in viewDidLoad
tableView.registerNib(UINib(nibName: "CustomCellXib", bundle: nil), forCellReuseIdentifier: "CustomCell")
Then do this in delegate method
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("CustomCell", forIndexPath: indexPath) as! CustomCell
cell.middleLabel.text = items[indexPath.row]
cell.leftLabel.text = items[indexPath.row]
cell.rightLabel.text = items[indexPath.row]
return cell
}
where CustomCellXib is your Xib file name.
CustomCell is your class of CustomCellXib
and #"CustomCell" is string identifier for reusing cells
Note down that you will have to implement other few delegates methods too for complete working of TableView.
There is nothing extremely complex here. It's a common UITableView with multiple sections.
Red text labels for every sections should be implemented as section headers
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
//create a view here
}
Custom UITableViewCell with grey labels, red - and + buttons in it.
Custom cell should contain a UIImageView below it's content. Since it is different for first, middle and last rows, you should set one of three images in cellForRow method depending on the cell's indexPath.row.
P.S. Don't listen to your iOS developer. You should not use UIWebView whenever you need to implement UI a bit more complex than default UITableView. Most probably he was joking ;)
I'm passing data to a custom UITableViewCell and based on that data I want to show or hide a dynamically added subview. I'm reusing a cell which is created in the storyboard. Everything is working as expected, until some of the cells are reused, for example while scrolling it will "randomly" hide or show the dynamic added subview.
What I need
I need a way to set the data of a cell through a method (setData), adding a dynamically created subview, while allowing a cell to be reused without creating glitches in its appearance, in particular the added subview as well the cells state.
Problem
I don't know where I should create the subview, so it doesn't have to be recreated when the cell is reused and so it won't bug when I want to hide or show it in the setData method. As well having access to the IBOutlet storyboardLabel while creating the new subview.
CustomTableViewCell
class CustomTableViewCell : UITableViewCell {
var data: DataItem?
var customSubview: UIView?
#IBOutlet weak var storyboardLabel: UILabel!
//setting the data of a cell and adding the subview
func setData(DataItem data) {
// adding the view
let customSubview = UIView.init(...)
customSubview.bounds = storyboardLabel.bounds
customSubview.hidden = data.showSubview
self.contentView.addSubview(customSubview)
}
}
Adding the cell
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("storyboardTableCell") as! CustomTableViewCell
cell.setData(self.data[indexPath.section][indexPath.row] as! DataItem)
return cell
}
Everything is working as expected, until some of the cells are reused...
Nothing is working as expected: you are adding object to a cached UITableViewCell, and of course, when you are passed that cached cell again on a subsequent cellForRowAtIndexPath, you are adding new objects.
Consider using a collection of views in IB, each satisfying your cell organization, thus saving adding subviews programmatically.
You need to clean up your cell.
Either remove everything you have added in your cellForRowAtIndexPath
You can use tags and viewWithTag if you want to refrain from re-adding already existing views
Or implement prepareForReuse()
You can find an example (and a similar discussion) on this Stack Overflow post.
I am making an iOS app that relies on a table view. In each cell of the table view, there are 4 buttons aligned on the bottom. I have a cell class that is pretty standard and a feedController to handle the table and setting all the items of the cell.
Everything works fine on it but I can not figure out how to handle the button clicks within the cell. I can hard code it into my cell class, but then every 3 cells has the same interaction. Is there a way to pass the button click function from the cell class into the controller? I have tried checking the state from the controller and that has not worked.
Can you add a gesture recognizer as you're doing your cellForItemAtIndexPath? So I had something similar with a collection view, and what I did was as it within:
func collectionView(collectionView: UICollectionView!, cellForItemAtIndexPath indexPath: NSIndexPath!) -> UICollectionViewCell!
{
var cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as MyCollectionView
...
I would add a gesture recognizer to each cell
i.e.
cell.addGestureRecognizer(UITapGestureRecognizer(target: self, action:Selector("tapAction:")))
And then something like:
func tapAction(recognizer: UITapGestureRecognizer) {
...
}
so recognizer ends up being the specific item tapped, and I could take action accordingly (in my case, I had my datasource of items and I would find the item in an array by casting recognizer to a cell, finding the appropriate subview, and update values on it)
I would add code block properties to your cell class which the table can assign to deal with each button. In your cell, code each button handler to call the appropriate block, or pass an index for the button used in a single block.
See my answer here which has an example, but for a switch.
How can I get index path of cell on switch change event in section based table view
If after a few cells you get the same interaction, it's possibly because you're dequeueing a reusable cell, and you're getting the same cell.
Make sure to set your .setTarget() call for your buttons in your tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) data source every time the cell is dequeued. It would help if you shared how you're handling dequeuing to see if this is your issue.