移動UICollectionViewCell

- (void)handlelongGesture:(UILongPressGestureRecognizer *)longGesture {
    //判斷手勢狀態
    switch (longGesture.state) {
        case UIGestureRecognizerStateBegan:{
            //判斷手勢落點位置是否在路徑上
            NSIndexPath *indexPath = [self.collectionView indexPathForItemAtPoint:[longGesture locationInView:self.collectionView]];
            if (indexPath == nil) {
                break;
            }
            //在路徑上則開始移動該路徑上的cell
            [self.collectionView beginInteractiveMovementForItemAtIndexPath:indexPath];
        }
            break;
        case UIGestureRecognizerStateChanged:
            //移動過程當中隨時更新cell位置
            [self.collectionView updateInteractiveMovementTargetPosition:[longGesture locationInView:self.collectionView]];
            break;
        case UIGestureRecognizerStateEnded:
            //移動結束後關閉cell移動
            [self.collectionView endInteractiveMovement];
            break;
        default:
            [self.collectionView cancelInteractiveMovement];
            break;
    }
}


- (BOOL)collectionView:(UICollectionView *)collectionView canMoveItemAtIndexPath:(NSIndexPath *)indexPath{
    //返回YES允許其item移動
    return YES;
}


- (void)collectionView:(UICollectionView *)collectionView moveItemAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath*)destinationIndexPath {
    //取出源item數據
    id objc = [_dataSource objectAtIndex:sourceIndexPath.item];
    //從資源數組中移除該數據
    [_dataSource removeObject:objc];
    //將數據插入到資源數組中的目標位置上