I have a UITableView in my view controller, and inside the cell there's a horizontal UIScrollView and inside this scroll view, I created many instances of a custom UIView (loaded from NIB file)
UITableViewCell
-- UIScrollView
-- MyView: UIView
Now MyView is not detecting touches, userInteractionEnabled is set to YES on every view in the hierarchy and I tried both ways
Implement touchesEnded: in MyView
Add a UITapGestureRecognizer to it
Both ways don't work, I guess it's something related to the fact that I have a UIScrollView inside the UITableViewCell
I am writing the application in Swift, not Objective-C, I don't think it matters since I guess it's a UIKit issue but who knows.
If you have any hint, I am all ears.
Thank you
Alternative for this case is add UITableViewCustomCell and add UICollectionView with horizontal scroll in Custom cell . It is more optimized way than adding UIView in scroll view because you can greatly speed things up. Instead of instantiating a lot of cells, you just instantiate as many as needed, i.e. as many that are visible (this is handled automatically). If scrolling to an area in the list where there are "cells" that haven't got their visual representation yet, instead of instantiating new ones, you reuse already existing ones.
Related
I need to have iOS app with screen like this:
screen
The idea is when user start to scroll down the first UIView to move up until the second UIView reach the top where it will stick and only UICollectionView will continue to move up.
Currently I'm using this structure
UIScrollView (main scroll)
UIView (some banners)
UIView (UISegmentedControl)
UICollectionView (grid with items, scroll is disabled, main scroll is used)
I manage to do it, but I needed to set UICollectionView height constraint manually in the code (calculated based on all items in grid) in order to appear in UIScrollView (everything else is handled by AutoLayout in Storyboard). The problem with this is that UICollectionView think all cells are visible and load them, so the whole recycling & reusing thing does not work. It's even worst because I use willDisplayCell method on UICollectionView to load more data when last cell is displayed, but now it load all pages at once.
My question (actually they are 2)
How can I fix the issue above?
What is the right way to achieve this functionality? Maybe my whole approach is conceptually wrong?
Collection view is a scroll view itself. So maybe you could have same functionality only with Collection view with sections or even custom layout?
I want to add a subview to a UICollectionView in order to make a left panel that scrolls with the collectionview.
Using
[self.collectionView addSubview:myView]
all touches become disabled and I can no longer scroll the view. I've read that adding a subview to a collectionView like this is bad practice.. is this true? Why does it disable touches from reaching the collectionView event when
userInteractionEnabled = NO
I'm trying to do this: imgur link by grabbing the frame position of the first cell in each section, and adding a dot with to myView with the same y value.
Thanks for any help!
Adding subviews using the addSubview: method to a UICollectionView is very bad practice. It can cause a lot of different problems in the normal behaviour of the CollectionView. It can obstruct the views underneath it, capture the touch events, preventing them from reaching the actual scrollView inside the CollectionView, etc. The subviews added using this method will also not scroll as the other elements in the CollectionView do.
The correct way to do what you want is to implement a new type of UICollectionViewCell for the dots, and compute their locations in the prepareForLayout and layoutAttributesForElementsInRect: methods. Basically you'll have either one or two cells in each row. Which ones will have two rows will be determined by you in the methods I've mentioned.
In fact, Apple's docs have a perfect example that's even more complex than what you're trying you achieve. You should check it out from this link.
May I know the purpose of that scroll view ? Because, if you're looking for a subview that displays only a label or image etc., You can use custom collectionview cell instead if I am not wrong... Hope it helps :) :)
Take this about page for Things:
I'm having trouble creating something similar. I just want a UITableView under a UIView with a UIImageView and a UILabel in it.
If I use a UIViewController and so I can position the UITableView downward, I get this error: "Static table views are only valid when embedded in UITableViewController instances."
If I use a UITableViewController with a grouped style and use contentInset on self.tableView to move it down ([self.tableView setContentInset:UIEdgeInsetsMake(150,0,0,0)];) I can't figure out how to place a view above it. If I try to attach anything to self.view it crashes (obviously). Same happens if I attach anything to self.tableView.
I then tried making the UIView the header of my UITableView section (I only need one section) but I can't get it to move up enough. It just sits inside the UITableView almost.
How do I have a UITableView (grouped style) exist with a UIView above it?
This can be achieved easily using the tableHeaderView property of UITableView. If you are using Interface Builder (which it looks like you are), then you can just drag a UIView above the table view and it will be set as the table's header view. All you need is a UITableViewController; no need for UIViewController and manually laying it out.
That's because the view probably isn't placed on top of the table but rather within the table's section 0 header. Or, even more likely, the view in question is just a regular UITableViewCell with a 0 alpha background.
Either of these options would allow the top view to be scrolled out of frame as the user scrolls under every condition.
I recommend [MDAboutController] (https://github.com/mochidev/MDAboutController)
It's easy to integrate and you don't have to waste any time configuring the UITableView.
I have added a subview to my tableview and when ever the user scrolls the tableview, the subview scrolls with it. How do I prevent this? I know it's probably along the lines of not adding the view to the tableview's subviews, but I have no knowledge of any other ways to do this. Thanks.
If you want to make a view a subview of the table view, then you can make it floating (non-scrolling) by changing its origin.y value in the scrollViewDidScroll method.
-(void)scrollViewDidScroll:(UIScrollView *)scrollView {
self.iv.frame = CGRectMake(self.ivOrigin.x, self.ivOrigin.y + self.tableView.bounds.origin.y, self.iv.frame.size.width, self.iv.frame.size.height);
}
In this example, "iv" is a property for an image view, and "ivOrigin" is a property for the initial origin of the image view (defined when I created the image view and its frame in viewDidLoad).
The UITableView is built and intended to be a view of things that scroll.
So, you can either fight that, which as you're discovering is quite hard since everything about the component is built and focused around scrolling and fast display of a subset of the full list data... Or, you can not fight it and put your static item on top of the table as a fixed-position item.
If there's a reason you can't add the table view and your animate-out item in your main view, you can always add a custom UIView class that contains both the table view and your animated view. Have your custom view class expose the contained table view as a .table property, and the container you're putting things in can be tweaked to use "mycontainerObject.tableview" instead of just "tableview" where needed.
Yes, it's a little more work to write the custom UIView subclass and give it a couple properties to hold the UITableView and whatever UIView you're animating out.. but it's likely a lot safer in the long run than trying to "hack" into the UITableView's methods and view hierarchy to try to give it a "fixed in place" behavior.
I have a number of views that include tableviews, but other controls as well. Up till now I have been subclassing UIViewController and manually adding a tableview to it (with my other controls above/below it). Not too much hassle, other than having to manually handle the scrolling, and sometimes some resizing (if the table's content is dynamic).
I only just found that the tableHeaderView and tableFooterView of a UITableView can pretty much handle anything you throw at them. I guess I skimmed them previously, thinking they were related to section headers/footers when they are of course not related at all.
So with that in mind, and before I convert a bunch of classes over to subclass UITableViewController instead of UIViewController, is this standard practice? If I have a view, for example, that is mostly non-table content but with a dynamic tableview half way down, is it a good idea simply to use a UITableViewController and put everything around it in the header/footer?
The table view header and footer are scrolled with the table view's content. If you need them to always be visible, your current approach is the best. If you don't mind the header views being scrolled, you can indeed refactor your app.
A UIViewController manages a view hierarchy. If your view contains significant non-UITableView content, I would manage the view hierarchy with aUIViewController and include the UITableView as a subview in the view controller's view property.