1.添加长按手势

    UILongPressGestureRecognizer *longPresssGes = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressMethod:)];
    [self.myCollectionView addGestureRecognizer:longPresssGes];

2.处理手势关联

- (void)longPressMethod:(UILongPressGestureRecognizer *)longPressGes {
    // 判断手势状态
    switch (longPressGes.state) {
            
        case UIGestureRecognizerStateBegan: {
            
            // 判断手势落点位置是否在路径上(长按cell时,显示对应cell的位置,如path = 1 - 0,即表示长按的是第1组第0个cell). 点击除了cell的其他地方皆显示为null
            NSIndexPath *indexPath = [self.myCollectionView indexPathForItemAtPoint:[longPressGes locationInView:self.myCollectionView]];
            // 如果点击的位置不是cell,break
            if (nil == indexPath) {
                break;
            }
            NSLog(@"%@",indexPath);
            // 在路径上则开始移动该路径上的cell
            [self.myCollectionView beginInteractiveMovementForItemAtIndexPath:indexPath];
        }
            break;
            
        case UIGestureRecognizerStateChanged:
            // 移动过程当中随时更新cell位置
            [self.myCollectionView updateInteractiveMovementTargetPosition:[longPressGes locationInView:self.myCollectionView]];
            break;
            
        case UIGestureRecognizerStateEnded:
            // 移动结束后关闭cell移动
            [self.myCollectionView endInteractiveMovement];
            break;
        default:
            [self.myCollectionView cancelInteractiveMovement];
            break;
    }
}

3.数据源处理

- (void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath {
    NSDictionary *dic = self.myHobbiesArray[sourceIndexPath.row];
    [self.myHobbiesArray removeObject:dic];
    
    [self.myHobbiesArray insertObject:dic atIndex:destinationIndexPath.row];
}