Android - GridLayoutManager - 垂直加载列表中的项目？

Question

我有一个让我们说20项的清单。我希望能够像这样加载它们

1 11
2 12
3 13
4 14
5 15
6 16
7 17
8 18
9 19
10 20

我正在使用RecyclerView和GridLayoutManager使用GridLayoutManager(context, 2)，它加载项目如下

1 2
3 4
5 6
7 8
....

这不是我想要的输出

Answer 1

实现这一目标的最简单方法是将ArrayList相应地排序到所需的顺序，将你的arraylist传递给重新排列的TheArrayList函数获取新的ArrayList并将其传递给recycleler视图Adapter以实现上述顺序。

 public ArrayList<Integer> rearrangeTheArrayList(ArrayList<Integer> integerArrayList) {
    ArrayList<Integer> resultArrayList = new ArrayList<>();
    int halfLength = 0;
    if (integerArrayList.size() % 2 == 1) {
        halfLength = (integerArrayList.size() / 2) + 1;
    } else {
        halfLength = integerArrayList.size() / 2;
    }

    for (int i = 0; i < halfLength; i++) {
        resultArrayList.add(integerArrayList.get(i));
        if ( (i + halfLength)<(integerArrayList.size() )) {
            resultArrayList.add(integerArrayList.get(i + halfLength));
        }
    }
    return resultArrayList;
}

Answer 2

GridLayoutManager总是教导RecyclerView从左到右，从上到下画画。此视图的默认缩放比例是垂直（或水平）。它无法计算在此动态情况下应显示的行数。我有一个解决方案给你。但是，您不应该保留此业务逻辑。

您只需要一个具有两种视图类型的适配器和用于索引正确事物的简单逻辑。示例代码：

public class SampleAdapter extends RecyclerView.Adapter<ViewHolder> {
    private final Context context;
    private List<Integer> listLeft;
    private List<Integer> listRight;

    public SampleAdapter (Context context) {
        this.context = context;
    }

    public void setListLeft(List<Integer> list) {
        this.listLeft = list;
    }

    public void setListRight(List<Integer> list) {
        this.listRight = list;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.sample, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        int index = position / 2; // assumes there are two lists of equal lengths
        int viewType = getItemViewType(position);
        if (viewType == TYPE_1) {
            holder.textView.setText(listLeft.get(index).toString());
        } else if (viewType == TYPE_2) {
            holder.textView.setText(listRight.get(index).toString());
        }
    }

    @Override
    public int getItemCount() {
        return listLeft.size() + listRight.size();
    }

    @Override
    public int getItemViewType(int position) {
        return position % 2 == 0 ? VIEW_TYPE_1 : VIEW_TYPE_2;
    }
}

Answer 3

您可以实现这样的逻辑。它会顺利运作

override fun onBindViewHolder(holder: RecyclerView.ViewHolder, pos: Int) {
            var arraySize = 21
            var half = 0
            if (array % 2 == 0)
                half = array % 2
            else half = (array % 2 + 0.5).toInt()
            if (pos  % 2 == 0)
                print(pos)
            else print(half + pos)
        }