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iOS UICollectionView的常用方法和属性

iOS UICollectionView的常用方法和属性

作者: 黑暗森林的歌者 | 来源:发表于2016-11-06 21:32 被阅读336次

    简单的创建和使用 collectionview 请看我的另一片文章,UICollectionView的简单使用

    下面是 UICollectionView 的常用方法和属性,或许可以通过详细阅读开发者文档从而做出来更炫的效果。

    //通过一个布局策略初识化CollectionView
    - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionViewLayout *)layout;
    
    //获取和设置collection的layout
    @property (nonatomic, strong) UICollectionViewLayout *collectionViewLayout;
    
    //数据源和代理
    @property (nonatomic, weak, nullable) id <UICollectionViewDelegate> delegate;
    @property (nonatomic, weak, nullable) id <UICollectionViewDataSource> dataSource;
    
    //从一个class或者xib文件进行cell(item)的注册
    - (void)registerClass:(nullable Class)cellClass forCellWithReuseIdentifier:(NSString *)identifier;
    - (void)registerNib:(nullable UINib *)nib forCellWithReuseIdentifier:(NSString *)identifier;
    
    //下面两个方法与上面相似,这里注册的是头视图或者尾视图的类
    //其中第二个参数是设置 头视图或者尾视图 系统为我们定义好了这两个字符串
    //UIKIT_EXTERN NSString *const UICollectionElementKindSectionHeader NS_AVAILABLE_IOS(6_0);
    //UIKIT_EXTERN NSString *const UICollectionElementKindSectionFooter NS_AVAILABLE_IOS(6_0);
    - (void)registerClass:(nullable Class)viewClass forSupplementaryViewOfKind:(NSString *)elementKind withReuseIdentifier:(NSString *)identifier;
    - (void)registerNib:(nullable UINib *)nib forSupplementaryViewOfKind:(NSString *)kind withReuseIdentifier:(NSString *)identifier;
    
    //这两个方法是从复用池中取出cell或者头尾视图
    - (__kindof UICollectionViewCell *)dequeueReusableCellWithReuseIdentifier:(NSString *)identifier forIndexPath:(NSIndexPath *)indexPath;
    - (__kindof UICollectionReusableView *)dequeueReusableSupplementaryViewOfKind:(NSString *)elementKind withReuseIdentifier:(NSString *)identifier forIndexPath:(NSIndexPath *)indexPath;
    
    //设置是否允许选中 默认yes
    @property (nonatomic) BOOL allowsSelection;
    
    //设置是否允许多选 默认no
    @property (nonatomic) BOOL allowsMultipleSelection;
    
    //获取所有选中的item的位置信息
    - (nullable NSArray<NSIndexPath *> *)indexPathsForSelectedItems; 
    
    //设置选中某一item,并使视图滑动到相应位置,scrollPosition是滑动位置的相关参数,如下:
    /*
    typedef NS_OPTIONS(NSUInteger, UICollectionViewScrollPosition) {
        //无
        UICollectionViewScrollPositionNone                 = 0,
        //垂直布局时使用的 对应上中下
        UICollectionViewScrollPositionTop                  = 1 << 0,
        UICollectionViewScrollPositionCenteredVertically   = 1 << 1,
        UICollectionViewScrollPositionBottom               = 1 << 2,
        //水平布局时使用的  对应左中右
        UICollectionViewScrollPositionLeft                 = 1 << 3,
        UICollectionViewScrollPositionCenteredHorizontally = 1 << 4,
        UICollectionViewScrollPositionRight                = 1 << 5
    };
    */
    - (void)selectItemAtIndexPath:(nullable NSIndexPath *)indexPath animated:(BOOL)animated scrollPosition:(UICollectionViewScrollPosition)scrollPosition;
    
    //将某一item取消选中
    - (void)deselectItemAtIndexPath:(NSIndexPath *)indexPath animated:(BOOL)animated;
    
    //重新加载数据
    - (void)reloadData;
    
    //下面这两个方法,可以重新设置collection的布局,后面的方法多了一个布局完成后的回调,iOS7后可以用
    //使用这两个方法可以产生非常炫酷的动画效果
    - (void)setCollectionViewLayout:(UICollectionViewLayout *)layout animated:(BOOL)animated;
    - (void)setCollectionViewLayout:(UICollectionViewLayout *)layout animated:(BOOL)animated completion:(void (^ __nullable)(BOOL finished))completion NS_AVAILABLE_IOS(7_0);
    
    //下面这些方法更加强大,我们可以对布局更改后的动画进行设置
    //这个方法传入一个布局策略layout,系统会开始进行布局渲染,返回一个UICollectionViewTransitionLayout对象
    //这个UICollectionViewTransitionLayout对象管理动画的相关属性,我们可以进行设置
    - (UICollectionViewTransitionLayout *)startInteractiveTransitionToCollectionViewLayout:(UICollectionViewLayout *)layout completion:(nullable UICollectionViewLayoutInteractiveTransitionCompletion)completion NS_AVAILABLE_IOS(7_0);
    //准备好动画设置后,我们需要调用下面的方法进行布局动画的展示,之后会调用上面方法的block回调
    - (void)finishInteractiveTransition NS_AVAILABLE_IOS(7_0);
    //调用这个方法取消上面的布局动画设置,之后也会进行上面方法的block回调
    - (void)cancelInteractiveTransition NS_AVAILABLE_IOS(7_0);
    
    //获取分区数
    - (NSInteger)numberOfSections;
    
    //获取某一分区的item数
    - (NSInteger)numberOfItemsInSection:(NSInteger)section;
    
    //下面两个方法获取item或者头尾视图的layout属性,这个UICollectionViewLayoutAttributes对象
    //存放着布局的相关数据,可以用来做完全自定义布局,后面博客会介绍
    - (nullable UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath;
    - (nullable UICollectionViewLayoutAttributes *)layoutAttributesForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath;
    
    //获取某一点所在的indexpath位置
    - (nullable NSIndexPath *)indexPathForItemAtPoint:(CGPoint)point;
    
    //获取某个cell所在的indexPath
    - (nullable NSIndexPath *)indexPathForCell:(UICollectionViewCell *)cell;
    
    //根据indexPath获取cell
    - (nullable UICollectionViewCell *)cellForItemAtIndexPath:(NSIndexPath *)indexPath;
    
    //获取所有可见cell的数组
    - (NSArray<__kindof UICollectionViewCell *> *)visibleCells;
    
    //获取所有可见cell的位置数组
    - (NSArray<NSIndexPath *> *)indexPathsForVisibleItems;
    
    //下面三个方法是iOS9中新添加的方法,用于获取头尾视图
    - (UICollectionReusableView *)supplementaryViewForElementKind:(NSString *)elementKind atIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(9_0);
    - (NSArray<UICollectionReusableView *> *)visibleSupplementaryViewsOfKind:(NSString *)elementKind NS_AVAILABLE_IOS(9_0);
    - (NSArray<NSIndexPath *> *)indexPathsForVisibleSupplementaryElementsOfKind:(NSString *)elementKind NS_AVAILABLE_IOS(9_0);
    
    //使视图滑动到某一位置,可以带动画效果
    - (void)scrollToItemAtIndexPath:(NSIndexPath *)indexPath atScrollPosition:(UICollectionViewScrollPosition)scrollPosition animated:(BOOL)animated;
    
    //用于动态添加,删除,移动某些分区获取items
    - (void)insertSections:(NSIndexSet *)sections;
    - (void)deleteSections:(NSIndexSet *)sections;
    - (void)reloadSections:(NSIndexSet *)sections;
    - (void)moveSection:(NSInteger)section toSection:(NSInteger)newSection;
    
    - (void)insertItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths;
    - (void)deleteItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths;
    - (void)reloadItemsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths;
    - (void)moveItemAtIndexPath:(NSIndexPath *)indexPath toIndexPath:(NSIndexPath *)newIndexPath;
    

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