Avoid animation of UICollectionView after reloadIt

问题:

UICollectionView animate items after reloadItemsAtIndexPaths is called (fade animation).

Is there a way to avoid this animation?

iOS 6

回答1:

You could also try this:

UICollectionView *collectionView;

...

[UIView setAnimationsEnabled:NO];

[collectionView performBatchUpdates:^{
    [collectionView reloadItemsAtIndexPaths:indexPaths];
} completion:^(BOOL finished) {
    [UIView setAnimationsEnabled:YES];
}];

Edit:

I have also found that if you wrap performBatchUpdates in a UIView animation block, the UIView animation is used instead of the default animation, so you can just set the animation duration to 0, like so:

[UIView animateWithDuration:0 animations:^{
    [collectionView performBatchUpdates:^{
        [collectionView reloadItemsAtIndexPaths:indexPaths];
    } completion:nil];
}];

This is extra cool if you want to use iOS 7 springy animations during inserts and deletes!

回答2:

It's worth noting that if you're targeting iOS 7 and above, you can use the new UIView method performWithoutAnimation:. I suspect that under the hood this is doing much the same as the other answers here (temporarily disabling UIView animations / Core Animation actions), but the syntax is nice and clean.

So for this question in particular...

Objective-C:

[UIView performWithoutAnimation:^{
    [self.collectionView reloadItemsAtIndexPaths:indexPaths];
}];

Swift:

UIView.performWithoutAnimation {
    self.collectionView.reloadItemsAtIndexPaths(indexPaths)
}

Of course this principle can be applied for any situation that you want to ensure a change is not animated.

回答3:

UICollectionView animate items after reloadItemsAtIndexPaths is called (fade animation).

Is there a way to avoid this animation?

iOS 6

I assume you're using a FlowLayout. Since you're trying to get rid of the fade animation, try this:

import UIKit

class NoFadeFlowLayout: UICollectionViewFlowLayout {

    override func initialLayoutAttributesForAppearingItem(at itemIndexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
        let attrs = super.initialLayoutAttributesForAppearingItem(at: itemIndexPath)
        attrs?.alpha = 1.0
        return attrs
    }

    override func finalLayoutAttributesForDisappearingItem(at itemIndexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
        let attrs = super.finalLayoutAttributesForDisappearingItem(at: itemIndexPath)
        attrs?.alpha = 1.0
        return attrs
    }

}

This is a very old question, so you're probably not targeting iOS 6 anymore. I was personally working on tvOS 11 and had the same question, so this is here for anyone who comes along with the same problem.

回答4:

I wrote a category on UICollectionView to do just that. The trick is to disable all animations while reloading:

if (!animated) {
    [CATransaction begin];
    [CATransaction setValue:(id)kCFBooleanTrue forKey:kCATransactionDisableActions];
}

[self reloadItemsAtIndexPaths:indexPaths];

if (!animated) {
    [CATransaction commit];
}

回答5:

Here is a Swift 3 version to performBatchUpdates without animation to a UICollectionView. I found this to work better for me than collectionView.reloadData() because it reduced cell swapping when records were inserted.

func appendCollectionView(numberOfItems count: Int){

        // calculate indexes for the items to be added
        let firstIndex = dataItems.count - count
        let lastIndex = dataItems.count - 1

        var indexPaths = [IndexPath]()
        for index in firstIndex...lastIndex {
            let indexPath = IndexPath(item: index, section: 0)
            indexPaths.append(indexPath)
        }

   UIView.performWithoutAnimation {

        self.collectionView.performBatchUpdates({ () -> Void in
            self.collectionView.insertItems(at: indexPaths)
        }, completion: { (finished) -> Void in

        })
    }
}

回答6:

extension UICollectionView {
    func reloadWithoutAnimation(){
        CATransaction.begin()
        CATransaction.setValue(kCFBooleanTrue, forKey: kCATransactionDisableActions)
        self.reloadData()
        CATransaction.commit()
    }
}

回答7:

- (void)reloadCollectionViewAnimated:(BOOL)animated  {

    if (animated) {
        [self.collectionView performBatchUpdates:^{
            [self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:0]];
        } completion:^(BOOL finished) {

        }];
    } else {
        [CATransaction begin];
        [CATransaction setValue:(id)kCFBooleanTrue forKey:kCATransactionDisableActions];
        [self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:0]];
        [CATransaction commit];
    }

}

回答8:

Just to add my $0.02, I tried both versions of the selected answer, and the original way worked better for my purposes. I am working on an infinite scrolling calendar view that allows for a user to enter the calendar at a given week and then swipe back and forth and select individual days for filtering a list.

In my implementation, in order to keep things performant on older devices the array of dates that represent the calendar view has to be kept relatively small which means holding about 5 weeks worth of dates, with the user in the middle at the 3rd week. The issue with using the second approach is, there's a second step where you have to scroll the collection view back to the middle without an animation, which makes for a very jagged appearance for some reason with the blocked base animation.

My Code:

[UIView setAnimationsEnabled:NO];
[self.collectionView performBatchUpdates:^{
    [self.collectionView deleteItemsAtIndexPaths:indexPathDeleteArray];
    [self.collectionView insertItemsAtIndexPaths:indexPathAddArray];

} completion:NULL];
[UIView setAnimationsEnabled:YES];

NSIndexPath *newIndexPath = [NSIndexPath indexPathForItem:14 inSection:0];
[self.collectionView scrollToItemAtIndexPath:newIndexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:NO];