版本记录
| 版本号 | 时间 |
|---|---|
| V1.0 | 2018.01.25 |
前言
2017年iOS版本更新到了11.0的系统，新机器比如iPhone X都是预装11.0的系统，而我们的UIKit框架中的UICollectionView类都做了哪些更改?接下来我们就看一下iOS11.0中UICollectionView类的改变，很多处新增，改动的还是很大的，下面我们就详细的看一下。由于前面几篇写了UITableView新增，里面已经详细的介绍了新增的内容，所以这里UICollectionView只列出来了改变的内容，不具体说明使用方法，感兴趣的可以参考。
1. 浅谈iOS 11.0中UITableView 都更改了什么？ （一）
2. 浅谈iOS 11.0中UITableView 都更改了什么？ （二）
3. 浅谈iOS 11.0中UITableView 都更改了什么？ （三）
@property (nonatomic, weak, nullable) id dragDelegate
@property (nonatomic, weak, nullable) id dragDelegate API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos);
@property (nonatomic, weak, nullable) id dropDelegate
@property (nonatomic, weak, nullable) id dropDelegate API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos);
@property (nonatomic) BOOL dragInteractionEnabled
/* To enable intra-app drags on iPhone, set this to YES.
* You can also force drags to be disabled for this collection view by setting this to NO.
* By default, For iPad this will return YES and iPhone will return NO.
*/
@property (nonatomic) BOOL dragInteractionEnabled API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos);
@property (nonatomic) UICollectionViewReorderingCadence reorderingCadence
/* Reordering cadence affects how easily reordering occurs while dragging around a reorder-capable drop destination.
* Default is UICollectionViewReorderingCadenceImmediate.
*/
@property (nonatomic) UICollectionViewReorderingCadence reorderingCadence API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos);
@property (nonatomic, readonly) BOOL hasUncommittedUpdates
// Returns YES if the collection view is reordering or has drop placeholders.
@property (nonatomic, readonly) BOOL hasUncommittedUpdates API_AVAILABLE(ios(11.0));
@property (nonatomic, readonly) BOOL hasActiveDrag
/* YES if a drag session is currently active. A drag session begins after items are "lifted" from the collection view.
*/
@property (nonatomic, readonly) BOOL hasActiveDrag API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos);
@property (nonatomic, readonly) BOOL hasActiveDrop
/* YES if collection view is currently tracking a drop session.
*/
@property (nonatomic, readonly) BOOL hasActiveDrop API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos);
代理UICollectionViewDragDelegate
API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos)
@protocol UICollectionViewDragDelegate
@required
/* Provide items to begin a drag associated with a given indexPath.
* If an empty array is returned a drag session will not begin.
*/
- (NSArray *)collectionView:(UICollectionView *)collectionView itemsForBeginningDragSession:(id)session atIndexPath:(NSIndexPath *)indexPath;
@optional
/* Called to request items to add to an existing drag session in response to the add item gesture.
* You can use the provided point (in the collection view's coordinate space) to do additional hit testing if desired.
* If not implemented, or if an empty array is returned, no items will be added to the drag and the gesture
* will be handled normally.
*/
- (NSArray *)collectionView:(UICollectionView *)collectionView itemsForAddingToDragSession:(id)session atIndexPath:(NSIndexPath *)indexPath point:(CGPoint)point;
/* Allows customization of the preview used for the item being lifted from or cancelling back to the collection view.
* If not implemented or if nil is returned, the entire cell will be used for the preview.
*/
- (nullable UIDragPreviewParameters *)collectionView:(UICollectionView *)collectionView dragPreviewParametersForItemAtIndexPath:(NSIndexPath *)indexPath;
/* Called after the lift animation has completed to signal the start of a drag session.
* This call will always be balanced with a corresponding call to -collectionView:dragSessionDidEnd:
*/
- (void)collectionView:(UICollectionView *)collectionView dragSessionWillBegin:(id)session;
/* Called to signal the end of the drag session.
*/
- (void)collectionView:(UICollectionView *)collectionView dragSessionDidEnd:(id)session;
/* Controls whether move operations (see UICollectionViewDropProposal.operation) are allowed for the drag session.
* If not implemented this will default to YES.
*/
- (BOOL)collectionView:(UICollectionView *)collectionView dragSessionAllowsMoveOperation:(id)session;
/* Controls whether the drag session is restricted to the source application.
* If YES the current drag session will not be permitted to drop into another application.
* If not implemented this will default to NO.
*/
- (BOOL)collectionView:(UICollectionView *)collectionView dragSessionIsRestrictedToDraggingApplication:(id)session;
@end
代理UICollectionViewDropDelegate
API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos)
@protocol UICollectionViewDropDelegate
@required
/* Called when the user initiates the drop.
* Use the dropCoordinator to specify how you wish to animate the dropSession's items into their final position as
* well as update the collection view's data source with data retrieved from the dropped items.
* If the supplied method does nothing, default drop animations will be supplied and the collection view will
* revert back to its initial pre-drop session state.
*/
- (void)collectionView:(UICollectionView *)collectionView performDropWithCoordinator:(id)coordinator;
@optional
/* If NO is returned no further delegate methods will be called for this drop session.
* If not implemented, a default value of YES is assumed.
*/
- (BOOL)collectionView:(UICollectionView *)collectionView canHandleDropSession:(id)session;
/* Called when the drop session begins tracking in the collection view's coordinate space.
*/
- (void)collectionView:(UICollectionView *)collectionView dropSessionDidEnter:(id)session;
/* Called frequently while the drop session being tracked inside the collection view's coordinate space.
* When the drop is at the end of a section, the destination index path passed will be for a item that does not yet exist (equal
* to the number of items in that section), where an inserted item would append to the end of the section.
* The destination index path may be nil in some circumstances (e.g. when dragging over empty space where there are no cells).
* Note that in some cases your proposal may not be allowed and the system will enforce a different proposal.
* You may perform your own hit testing via -[UIDropSession locationInView]
*/
- (UICollectionViewDropProposal *)collectionView:(UICollectionView *)collectionView dropSessionDidUpdate:(id)session withDestinationIndexPath:(nullable NSIndexPath *)destinationIndexPath;
/* Called when the drop session is no longer being tracked inside the collection view's coordinate space.
*/
- (void)collectionView:(UICollectionView *)collectionView dropSessionDidExit:(id)session;
/* Called when the drop session completed, regardless of outcome. Useful for performing any cleanup.
*/
- (void)collectionView:(UICollectionView *)collectionView dropSessionDidEnd:(id)session;
/* Allows customization of the preview used for the item being dropped.
* If not implemented or if nil is returned, the entire cell will be used for the preview.
*
* This will be called as needed when animating drops via -[UICollectionViewDropCoordinator dropItem:toItemAtIndexPath:]
* (to customize placeholder drops, please see UICollectionViewDropPlaceholder.previewParametersProvider)
*/
- (nullable UIDragPreviewParameters *)collectionView:(UICollectionView *)collectionView dropPreviewParametersForItemAtIndexPath:(NSIndexPath *)indexPath;
@end
枚举UICollectionViewDropIntent
typedef NS_ENUM(NSInteger, UICollectionViewDropIntent) {
/* Collection view will accept the drop, but the location is not yet known and will be determined later.
* Will not open a gap. You may wish to provide some visual treatment to communicate this to the user.
*/
UICollectionViewDropIntentUnspecified,
/* The drop will be placed in item(s) inserted at the destination index path.
* Opens a gap at the specified location simulating the final dropped layout.
*/
UICollectionViewDropIntentInsertAtDestinationIndexPath,
/* The drop will be placed inside the item at the destination index path (e.g. the item is a container of other items).
* Will not open a gap. Collection view will highlight the item at the destination index path.
*/
UICollectionViewDropIntentInsertIntoDestinationIndexPath,
} API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos);
类UICollectionViewDropProposal
UIKIT_EXTERN API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos)
@interface UICollectionViewDropProposal : UIDropProposal
- (instancetype)initWithDropOperation:(UIDropOperation)operation intent:(UICollectionViewDropIntent)intent;
/* The default is UICollectionViewDropIntentUnspecified.
*/
@property (nonatomic, readonly) UICollectionViewDropIntent intent;
@end
协议UICollectionViewDropCoordinator
API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos)
@protocol UICollectionViewDropCoordinator
/* Ordered list of items available for this drop.
*/
@property (nonatomic, readonly) NSArray> *items;
/* The last hit-tested index path known during the drop session.
* If this is nil, the proposal's intent will be .unspecified
*/
@property (nonatomic, readonly, nullable) NSIndexPath *destinationIndexPath;
/* The current drop proposal at the time of the drop.
*/
@property (nonatomic, readonly) UICollectionViewDropProposal *proposal;
@property (nonatomic, readonly) id session;
/* Animate the dragItem to an automatically inserted placeholder item.
*
* A placeholder cell will be created for the reuse identifier and inserted at the specified indexPath without requiring a dataSource update.
*
* The cellUpdateHandler will be called whenever the placeholder cell becomes visible; -collectionView:cellForItemAtIndexPath: will not be called
* for the placeholder.
*
* Once the dragItem data is available, you can exchange the temporary placeholder cell with the final cell using
* the placeholder context method -commitInsertionWithDataSourceUpdates:
*
* UICollectionViewDropPlaceholderContext also conforms to UIDragAnimating to allow adding alongside animations and completion handlers.
*/
- (id)dropItem:(UIDragItem *)dragItem toPlaceholder:(UICollectionViewDropPlaceholder*)placeholder;
/* Animate the dragItem to a newly inserted item at the specified index path.
* You must call -performBatchUpdates:completion: to update your data source and insert a new item into the collection view prior to calling this method.
*
* To tweak the appearance of the preview being dropping (e.g. supply a clipping path), see -collectionView:dropPreviewParametersForItemAtIndexPath:
*/
- (id)dropItem:(UIDragItem *)dragItem toItemAtIndexPath:(NSIndexPath *)indexPath;
/* Animate the dragItem to a rect inside an existing item.
* The rect is in the coordinate space of the cell at this index path.
* The item will be animated with an aspect fit scale transform to fit inside the rect. Use a rect with zero size to shrink the item to a single point.
*/
- (id)dropItem:(UIDragItem *)dragItem intoItemAtIndexPath:(NSIndexPath *)indexPath rect:(CGRect)rect;
/* Animate the dragItem to a location specified by the UIDragPreviewTarget.
*/
- (id)dropItem:(UIDragItem *)dragItem toTarget:(UIDragPreviewTarget *)target;
@end
类UICollectionViewDropPlaceholder
UIKIT_EXTERN API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos,watchos)
@interface UICollectionViewDropPlaceholder : UICollectionViewPlaceholder
/* If specified, will be used to modify the appearance (e.g. visiblePath to supply a "cut out" region of the placeholder cell) of the animating dropped item.
* Handler will be called as-needed.
*/
@property (nonatomic, nullable, copy) UIDragPreviewParameters * _Nullable (^previewParametersProvider)(__kindof UICollectionViewCell *);
@end
协议UICollectionViewDropItem
API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos)
@protocol UICollectionViewDropItem
@property (nonatomic, readonly) UIDragItem *dragItem;
/* If this drop item is also from this collection view this indexPath will specify the location of the item.
* If the dragItem comes from some other source (e.g. another source inside or outside of the app), it will be nil.
* This is useful for directly accessing the model objects in the data source instead of using the item provider
* to retrieve the data.
*/
@property (nonatomic, readonly, nullable) NSIndexPath *sourceIndexPath;
/* May be useful for computing the UIDragPreviewTarget transform for UICollectionViewDropCoordinator dropItem:toTarget:
* Returns CGSizeZero if the dragItem does not have a visible drop preview.
*/
@property (nonatomic, readonly) CGSize previewSize;
@end
协议UICollectionViewDropPlaceholderContext
API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos)
@protocol UICollectionViewDropPlaceholderContext
/* Retrieve drop data from the dragItem's itemProvider.
*/
@property (nonatomic, readonly) UIDragItem *dragItem;
/* Exchange the placeholder for the final cell.
* You are only responsible for updating your data source inside the block using the provided insertionIndexPath.
* If the placeholder is no longer available (e.g. -reloadData has been called) the dataSourceUpdates block
* will not be executed and this will return NO.
*/
- (BOOL)commitInsertionWithDataSourceUpdates:(void(NS_NOESCAPE ^)(NSIndexPath *insertionIndexPath))dataSourceUpdates;
/* If the placeholder is no longer needed or you wish to manually insert a cell for the drop data, you can
* remove the placeholder via this method.
* If the placeholder is no longer available (e.g. -reloadData has been called) this will return NO.
*/
- (BOOL)deletePlaceholder;
/* Call this method to request an update of the placeholder cell's content via the updateCellHandler.
* This will only be called if the placeholder is visible. If the placeholder becomes visible via scrolling,
* the updateCellHandler will automatically be called.
*/
- (void)setNeedsCellUpdate;
@end
枚举 UICollectionViewReorderingCadence
typedef NS_ENUM(NSInteger, UICollectionViewReorderingCadence) {
UICollectionViewReorderingCadenceImmediate,
UICollectionViewReorderingCadenceFast,
UICollectionViewReorderingCadenceSlow
} API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos);
UICollectionViewDelegate新增方法
// Spring Loading
/* Allows opting-out of spring loading for an particular item.
*
* If you want the interaction effect on a different subview of the spring loaded cell, modify the context.targetView property.
* The default is the cell.
*
* If this method is not implemented, the default is YES.
*/
- (BOOL)collectionView:(UICollectionView *)collectionView shouldSpringLoadItemAtIndexPath:(NSIndexPath *)indexPath withContext:(id)context API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(tvos, watchos);
后记
本篇已结束，后面更精彩~~~
