Recently, I see a strange thing in Xcode 11.4.
When I create a UICollectionView with Its cell, adding TapGesture doesn't work. By debugging on its view in runtime, I noticed a view covers all the cells. It seems it is ContainerView.
This view prevents users to click or tap on items.
Any help is appreciated
Are you adding your subviews and tap gesture to the cell's contentView?
In the documentation for UICollectionViewCell (https://developer.apple.com/documentation/uikit/uicollectionviewcell), it says:
To configure the appearance of your cell, add the views needed to
present the data item’s content as subviews to the view in the
contentView property. Do not directly add subviews to the cell itself.
The same applies for UITableViewCell as well.
Related
edit mode problem
As you can see in the picture, when I enter the edit mode the delete button appears on top of all the views in the cell.
I assume this is because I am using programmatic UI with autolayouts not the storyboard and some of the constraints are preventing actions, but I cannot find out how I can resolve this issue.
I suspect that when creating your UITableViewCell subclass, you did not add your custom subviews to the cell's contentView.
From the documentation:
The content view of a UITableViewCell object is the default superview for content that the cell displays. If you want to customize cells by simply adding additional views, you should add them to the content view so they position appropriately as the cell transitions in to and out of editing mode.
Sounds like your problem exactly.
This question already has answers here:
Programmatically send to front/back elements created from interface builder
(2 answers)
Closed 10 days ago.
I am using a .xib for my cell in a table view. Inside the .xib, is another view (cellBackgroundView), and a button. When I run the app, and click the button, it does not respond at all. Instead, it calls the tableView's didSelectedRowAtIndexPath method which brings another view controller.
Using Xcode's Debug View Hierarchy, I discovered that I have a view overlaying the all the buttons (see pic attached: this overlaying view is highlighted). This view (called backgroundView) that is overlaying my button is a View, within a view. I have a feeling when you place a view in a view, and put a button in the initial view, the button isn't called because its below the view hierarchy.
How do I fix this issue? Is there a way to move background view to the back of the view heirarchy so that the buttons will be responsive?
Debug View hierarchy:
Structure of .xib
Two things that you could check
1) Do you have a delegate method for cell height and is the height returned correct? Unless you have Clip Subviews on for the UITableViewCell, the contents of the cell can be visible outside it's frame, but the parts that are outside the cell's frame are not registering user interactions.
2) Is some other view element higher in the hierarchy (lower in the XCode listing you posted) overlapping the button? iOS Simulators Debug -> Color Blended Layers can help spotting this.
Edit:
If I interpret the added screenshots correctly, you probably have the issue mentioned in the option 1) above. If the other elements showing in the screenshot are those listed as subviews of the Cell Background View they are mostly outside the parent view's frame and thus don't receive touch events. If the background view's frame is correct, then you might want to move the other elements as children for Feed Cell directly.
Also, the element listing suggests that you are using plain UIView as the parent element. I don't know the inner workings of your application, but if you only use this view in a UITableViewCell you might want to consider making the parent view a Table View Cell in the xib. This will reduce some bloat and allow you to configure some properties for the cell in the xib.
Maybe you forgot assign your Button to code
I assume Feed Cell is a subclass of UITableViewCell, and cellBackgroundView is the property contentView of this cell.
If so, the cells property backgroundView should be behind your cellBackgroundView (the docs say: UITableViewCell adds the background view as a subview behind all other views and uses its current frame location.).
You could set the cells property backgroundView = nil, and see whether it is still there in the view hierarchy. If so, you do add a custom backgroundView on top of the other cells views somewhere.
To check this, you could read out the subview hierarchy of your cell in your method tableView:cellForRowAtIndexPath: with something like NSArray *svs = cell.subviews; (assuming cell is the tableViewCell) and set a breakpoint behind this statement.
svs usually contains first the UITableViewCellContentView, and above it the _UITableViewCellSeparatorView. The cells backGroundView will not be shown. You could check there your view hierarchy.
If by chance there is a custom backgroundView on top, you could - as a workaround, not a solution - bring the contentView to the front by sending to the cell bringSubviewToFront: with the contentView as argument. Then the button should respond.
In your Structure of Xib Place your button below the view that is first the view is added to superView then the Button, then your button will work.
or you can code
-(void)viewDidLayoutSubviews{
[self.view insertSubview:yourButton aboveSubview:cellBackgroundView];
}
Hope it will help.
Do you add an UIButton by code?
If so you should ensure you addSubview: into cell.contentView and not into cell.
Also you could try to apply CellBackground class to a view inside contentView, not directly to contentView.
you can use this method.
[cell.contentView bringSubviewToFront:yourButton];
after that if you want to back in background then tou can use sendSubviewToBack: method .
After adding this methods your button is not responding set the userIntractionEable of button's superview.
I have a UITableView that I've created in a UIStoryboard. It contains one Prototype UITableViewCell. The cells are populated in the ViewController's cellForRowAtIndexPath: method.
I'm now trying to add the ability to delete cells using commitEditingStyle:forRowAtIndexPath:. Everything is working except that when the delete button animates over the cell, the rest of the content doesn't shift over and it looks really ugly. According to this SO question, content will only be shifted if it's added to the cell's contentView rather than to the cell itself.
As such, is there a way to add a UIView (Ex. a UIButton) to a UITableViewCell's contentView within a UIStoryboard?
I have a UICollectionView with a custom UICollectionViewCell. The UICollectionView scrolls horizontally, with each cell occupying all of the visible screen.
The UICollectionViewCell has a UIView subview, which in turn has a UIScrollView subview.
The UIScrollView is intended to scroll vertically, but it's not scrolling at all. I've tried setting the scroll view's contentSize with no success.
I suspect that the UIScrollView is not getting any touch events rather than it being a size issue.
Any suggestions?
EDIT >>
I'm now sure it's an event problem rather than anything specific to the UIScrollView.
I've now overridden the pointInside: method in the UIView in the UICollectionViewCell and can see that it now returns false every time I tap on it. In that case you'd think that the tap event would propagate to the next subview , but the UIView still isn't getting events. I've tried adding a UIGestureRecognizer to the UIView but it never registers a tap.
Could there be anything here intercepting the events that I'm not aware of?
I've been trying to solve a similar problem with a scrollview, and your edit about events reminded me of this question (which solved my problem again) How can I use a UIButton in a UICollection supplementary view?
Its possible you need to be using a UICollectionReusableView, not a UICollectionViewCell. Changing the class worked for me because I was using a button (and recently a scrollview) in a header.
However I've not tried for cells themselves. For capturing events from a UICollectionViewCell, maybe the following may help?
Getting button action : UICollectionView Cell
Try to disable userInteractionEnabled for the UIView and enable it for your UIScrollView
I'm not sure if this was your problem, but it was mine - and I'm putting it here in case anyone else comes across this for the same reason. I wanted to put a UIScrollView inside a UICollectionReusableView but by accident I had created my custom class as;
class CustomCellHeader: UICollectionViewCell {
}
instead of;
class CustomCellHeader: UICollectionReusableView {
}
Once I changed that, the UIScrollView within my header cell came to life!
Embed the scrollable content in a ScrollView within the cell.
Add "UICollectionViewDelegateFlowLayout" to the UICollectionViewCell i.e.:
class SomeCollectionCell: UICollectionViewCell, UICollectionViewDelegateFlowLayout {
}
Now scrolling within the cell should work.
When I reorder my UITableViewCells, the Subviews of the Cell are not visible while dragging...I get always the same result, whether I add the Subviews programmatically in a UITableViewCell Subclass or in Storyboard...
Is there a possibility to see the real UITableViewCell with Subviews while dragging?
Ok I found a solution by my self...
For some reason the mysterious reordering animation from Apple cant capture simple UIViews, but with UIImageViews, UIButtons and UILabels as Subviews of the custom TableViewCell, the animation works like expected...creepy!