Cells Overlapping
I used custom class for UITableViewCell. It look fine
but the debug view Hierarchy cells is overlapping as image above.
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier(self.reuseIdentify, forIndexPath: indexPath) as! ContactViewCell
cell.lbContactName.text = self.dataSource[indexPath.row]
return cell
}
Please check the custom UITableviewCell Clip Subviews property.
Related
Adding views programmatically into tableView cells making scroll jerky and slow. I am adding views programmatically into cell in the delegate function "CellForRowAt". I tried it through delegate function "WillDisplay" but the results are the same.
What is the best possible solution to achieve this?
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier:
"cell", for: indexPath) as! CustomCell
addViewsInCell(cell: cell, indexPath: indexPath)
return cell
}
func addViewsInCell(cell: CustomCell, indexPath: IndexPath) {
//here i am adding some views programmatically
for i in 0..<3 {
let customView: CustomView = Bundle.main.loadNibNamed("CustomView", owner: self, options: nil)![0] as! customView
cell.customViewPlacement.addSubview(customView)
}
}
Cell views are reused. Adding a subview every time in cellForRowAt indexPath: you end up with multiple copies of the same subview. Instead you should check whether that subview is already added. You could mark your subview with a tag and then use the viewWithTag method to test its presence.
Don't add any subviews/custom views inside tableView: cellForRowAt indexPath:. This will cause those subviews to be added repeatedly whenever that cell loaded by the table view. Instead create a subclass of UITableViewCell and create your subviews inside that subclass if you are working programmatically. Or else if you are working with storyboards, you can create a dynamic prototype cell.
I created two ViewControllers and two TableViews. Then i added prototype cell to one TableView, set it up according to my needs, copied it to the other TableView, changed its class and identifier and linked it up in ViewController that is datasource and delegate for each one.
The problem is, FEEDING one is behaving good, having constraints as expected, and the WALKING one is not, but i have no idea why since they have all same properties in each one's:
ViewControllers:
FEEDING
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = myFeedingTableView.dequeueReusableCellWithIdentifier("feedingcell", forIndexPath: indexPath) as! FeedingCell
cell.time.text = self.vremena[indexPath.row]
return cell
}
WALKING
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = myWalkingTableView.dequeueReusableCellWithIdentifier("walkingcell", forIndexPath: indexPath) as! WalkingCell
cell.time.text = self.vremena[indexPath.row]
return cell
}
CustomCell files
each one is connected to its class
FeedingCell is class of feeding prototype cell
WalkingCell is class of feeding prototype cell
Constraints
and the constraints are same, as you can see on the picture.
Here is the image providing different results and constraints:
image
Solved by changing rowHeight settings in TableView. Thanks #SilentLupin
Having a UITableViewControllerand using:
override func tableView(tableView: UITableView, cellForRowAtIndexPath
indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("reuseIdentifier", forIndexPath: indexPath) as! UITableViewCell
return cell
}
Using dequeueReusableCellWithIdentifier:forIndexPath:'' instead ofdequeueReusableCellWithIdentifier`` how can I determine if a cell is a new one or a reused one?
Create your own custom cell class to use for the reuse identifier. Then, inside that cell, implement awakeFromNib and make your changes to the cell. This will only be called once when your cell is loaded from its NIB file.
Any other changes that need to be made when the cell is reused can be made in prepareForReuse.
I have multiple UICollectionViewCells. When the user taps on a specific cell, I would like my app to change the background image of the touched cell.
My approach is to focus on the didSelectItemAtIndexPath method. When a cell is touched, this method will be called.
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
var cell: UICollectionViewCell = collectionView.dequeueReusableCellWithReuseIdentifier("cellIdentifier", forIndexPath: indexPath) as! UICollectionViewCell
cell.backgroundView = UIImageView(image: UIImage(named: "myImage"))
}
However, I can't get it working but I don't know why. The issue is probably related to indexPath, that doesn't return a correct value of the cell. I tried using indexPath.row and this does actually return an Int number of the cell.
What's more, I'm also creating a new UICollectionViewCell with var but this cell already exists.
Why isn't the cell updating its background image? How do I change the background image of a UICollectionViewCell that has been touched by the user?
I totally agree with the Josh's answer, but if you change the background image using the didSelectItemAtIndexPath method it works fine as well. Then, you can use the cellForRowAtIndexPath method that returns the UITableViewCell at the specified indexPath, like in the following way:
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
var cell = tableView.cellForRowAtIndexPath(indexPath) as UITableViewCell!
cell.backgroundView = UIImageView(image: UIImage(named: "photo2"))
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! UITableViewCell
cell.backgroundView = UIImageView(image: UIImage(named: "photo1"))
cell.selectionStyle = .None
return cell
}
I just put the selectionStyle to .None to avoid the highlight. I hope this help you.
Using Swift: I've hooked up an NSFetchedResultsController to a UITableView, and created a subclass of UITableViewCells for the TableView cells.
The UITableViewCells format and display correctly. But the app crashes as soon as I try editing the rows (adding or deleting).
For testing, I've used the most basic subclass possible: An empty subclass, and it still crashes. The original UITableViewCell works normally.
Any ideas? Swift bug? The crash goes straight to the top of the stack. I get nothing in the console.
Works:
override func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell? {
var cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell
let task = fetchedResultController.objectAtIndexPath(indexPath) as Tasks
cell.textLabel.text = task.desc
return cell
}
Doesn't work:
override func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell? {
var cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell2
let task = fetchedResultController.objectAtIndexPath(indexPath) as Tasks
cell.textLabel.text = task.desc
return cell
}
When subclass is:
import UIKit
class UITableViewCell2: UITableViewCell {
}
If you create table cells programmatically (not in InterfaceBuilder) you have to register the table cell class with
TableView.registerClass(..., forCellReuseIdentifier...)