iOS9 UICollectionView新推出的Item排序方法

协议签订
创建UICollectionView
指定代理人
添加手势
手势方法实现
代理方法实现

UICollectionView协议签订 添加属性

@interface ZGLSubscribeCell () <UICollectionViewDataSource ,UICollectionViewDelegate>@property (nonatomic, strong) UICollectionView *subscribeCollectionView;

创建UICollectionView

UICollectionViewFlowLayout *flow = [[UICollectionViewFlowLayout alloc] init];/* ScaleX pch文件中定义的宏 用于适配屏幕尺寸 */    flow.itemSize = CGSizeMake(ScaleX * 375 / 3, ScaleX * 375 / 3);    flow.minimumInteritemSpacing = 0;    flow.minimumLineSpacing = 0;    flow.scrollDirection = 0;    self.subscribeCollectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0,ScaleX * 375, ScaleX * 375) collectionViewLayout:flow];    /* 指定代理人 */    self.subscribeCollectionView.delegate = self;    self.subscribeCollectionView.dataSource = self;    self.subscribeCollectionView.backgroundColor = [UIColor whiteColor];    /* UICollectionView注册cell的方法 */    [self.subscribeCollectionView registerClass:[ZGLSubscribeCollectionViewViewCell class] forCellWithReuseIdentifier:@"ZGLSubscribeCell_ZGLSubscribeCollectionViewViewCell"];    [self.subscribeCollectionView registerClass:[ZGLAddOptionsCell class] forCellWithReuseIdentifier:@"ZGLSubscribeCell_ZGLAddOptionsCell"];    /* 此处给其增加长按手势，用此手势触发cell移动效果 */    UILongPressGestureRecognizer *longGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handlelongGesture:)];    [self.subscribeCollectionView addGestureRecognizer:longGesture];    [self.contentView addSubview:self.subscribeCollectionView];

长按手势方法实现

- (void)handlelongGesture:(UILongPressGestureRecognizer *)longGesture {    /* 判断手势状态 */    switch (longGesture.state) {        case UIGestureRecognizerStateBegan:{            /* 判断手势落点位置是否在路径上 */                        NSIndexPath *indexPath = [self.subscribeCollectionView indexPathForItemAtPoint:[longGesture locationInView:self.subscribeCollectionView]];            if (indexPath == nil) {                break;            }            /* 在路径上则开始移动该路径上的cell */            [self.subscribeCollectionView beginInteractiveMovementForItemAtIndexPath:indexPath];        }            break;        case UIGestureRecognizerStateChanged:            /* 移动过程当中随时更新cell位置 */            [self.subscribeCollectionView updateInteractiveMovementTargetPosition:[longGesture locationInView:self.subscribeCollectionView]];            break;        case UIGestureRecognizerStateEnded:            /* 移动结束后关闭cell移动 */            [self.subscribeCollectionView endInteractiveMovement];            break;        default:            [self.subscribeCollectionView cancelInteractiveMovement];            break;    }}

允许移动的item

- (BOOL)collectionView:(UICollectionView *)collectionView canMoveItemAtIndexPath:(NSIndexPath *)indexPath{    /* 返回YES允许其item移动 */        return YES;}

对交换过的item数据进行操作

- (void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath*)destinationIndexPath {    /* 交换资源数组中移动item和目标位置item的资源位置 */        [self.optionsArr exchangeObjectAtIndex:sourceIndexPath.item withObjectAtIndex:destinationIndexPath.item];        [self.subscribeCollectionView reloadData];}

抑制item移动

- (NSIndexPath *)collectionView:(UICollectionView *)collectionView targetIndexPathForMoveFromItemAtIndexPath:(NSIndexPath *)originalIndexPath toProposedIndexPath:(NSIndexPath *)proposedIndexPath {    /* 可以指定位置禁止交换 */    if (proposedIndexPath.item == _optionsArr.count) {        return originalIndexPath;    } else {        return proposedIndexPath;    }}