IOS CollectionView 拖拽移动

collection 增加长按手势

   //添加长按的手势     UILongPressGestureRecognizer *longPress=[[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(longPress:)];   [collectionView addGestureRecognizer:longPress];

- (void)longPress:(UIGestureRecognizer *)longPress {    //获取点击在collectionView的坐标    CGPoint point=[longPress locationInView:self.collectionView];    //从长按开始    if (longPress.state == UIGestureRecognizerStateBegan) {        NSIndexPath *indexPath=[self.collectionView indexPathForItemAtPoint:point];        [self.collectionView beginInteractiveMovementForItemAtIndexPath:indexPath];        //长按手势状态改变    } else if(longPress.state==UIGestureRecognizerStateChanged) {        [self.collectionView updateInteractiveMovementTargetPosition:point];        //长按手势结束    } else if (longPress.state==UIGestureRecognizerStateEnded) {        [self.collectionView endInteractiveMovement];        //其他情况    } else {        [self.collectionView cancelInteractiveMovement];    }}- (NSIndexPath *)collectionView:(UICollectionView *)collectionView targetIndexPathForMoveFromItemAtIndexPath:(NSIndexPath *)originalIndexPath toProposedIndexPath:(NSIndexPath *)proposedIndexPath {    /* 两个indexpath参数, 分别代表源位置, 和将要移动的目的位置*/    //-1 是为了不让最后一个可以交换位置    if (proposedIndexPath.item == (_dataArrays.count - 1)) {        //初始位置        return originalIndexPath;    } else {    //-1 是为了不让最后一个可以交换位置        if (originalIndexPath.item == (_dataArrays.count - 1)) {            return originalIndexPath;        }//      移动后的位置        return proposedIndexPath;    }}-(void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath{        //记录要移动的数据        id object= self.dataArrays[sourceIndexPath.item];        //删除要移动的数据        [self.dataArrays removeObjectAtIndex:sourceIndexPath.item];        //添加新的数据到指定的位置        [self.dataArrays insertObject:object atIndex:destinationIndexPath.item];}