问题
I want to animate the collectionview cells,the animations should be like this:
First Cell Appear and then after some delay second cell will appear with some animations,this will go on like this for all the cells.
How to achieve this?
回答1:
A solution would be to create the datasource incrementally so you add a cell after a set timed delay. Once added, insert
Make a call to set up a timer to add to your dataSource with whatever delay you like
[NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(addToDataSource:) userInfo:nil repeats:YES];
Then within this method that will hit every 0.05 seconds (in this example)
-(void)addToDataSource:(NSTimer*)timer{
[self.yourMutableDataSourceArray addObject:OBJECT]
NSInteger arrayCount = self.yourMutableDataSourceArray.count;
[self.collectionView performBatchUpdates:^{
[self.collectionView insertItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:arrayCount-1 inSection:0]]];
} completion:^(BOOL finished) {
}];
//Once you have reached the desired count cells you wish, remember to invalidate the timer
}
The performBatchUpdate
will mean the collectionView will be reloaded with animation.
I hope this helps
This is in objective-C, though same principles apply if you're writing this in swift
回答2:
The other solution here is using willDisplayCell:forIndexPath
delegate
Here is a sample how i do it.
func collectionView(collectionView: UICollectionView, willDisplayCell cell: UICollectionViewCell, forItemAtIndexPath indexPath: NSIndexPath) {
if (!loadedIdx.contains(indexPath.row)) {
let cellContent = cell
let rotationAngleDegrees : Double = -30
let rotationAngleRadians = rotationAngleDegrees * (M_PI/180)
let offsetPositioning = CGPoint(x: collectionView.bounds.size.width, y: -20)
var transform = CATransform3DIdentity
transform = CATransform3DRotate(transform, CGFloat(rotationAngleRadians), -50, 0, 1)
transform = CATransform3DTranslate(transform, offsetPositioning.x, offsetPositioning.y, -50)
cellContent.layer.transform = transform
cellContent.layer.opacity = 0.2
let delay = 0.06 * Double(indexPath.row)
UIView.animateWithDuration(0.8, delay:delay , usingSpringWithDamping: 0.8, initialSpringVelocity: 0.5, options: .CurveEaseIn, animations: { () -> Void in
cellContent.layer.transform = CATransform3DIdentity
cellContent.layer.opacity = 1
}) { (Bool) -> Void in
}
loadedIdx.append(indexPath.row)
}
}
The loadedIdx is an array to mark cell as loaded ( not animate in the next time appear)
来源:https://stackoverflow.com/questions/38435196/uicollectionviewcell-animations