Question

我正在使用expandablelistview。无论如何我可以在单击里面的图像时展开组行？我知道要让图像响应点击，我必须设置它的焦点。现在，一旦此图像响应click（在我的客户适配器内），我如何以编程方式扩展/折叠它所属的特定组行？

谢谢

Answer 1

在适配器

中

private OnItemSelectedListener onItemSelectedCallback;

public interface OnItemsSelectedListener {
    public void onImageSelected(int groupPos);
}

public YourAdapter(Context context) {
    try {
        this.onItemSelectedCallback = (OnItemSelectedListener ) context;
    }
    catch (ClassCastException e) {
        throw new ClassCastException(context.toString() + " must implement OnItemSelectedListener ");
    }
}

在getView（）

中添加它

ImageView imageView = new ImageView();
imageView.setTag(R.id.tagGroupPosition, groupPosition);
imageView.setOnClickListener(onClickListener);

在OnClickListener中添加此内容

OnClickListener onClickListener = new OnClickListener() {
    @Override
    public void onClick(View v) {
        int groupPos = ((ImageView) v).getTagId(R.id.tagGroupPosition);
        onItemSelectedCallback.onImageSelected(groupPos);
    }
}

然后在活动中你必须实现YourAdapter.OnItemsSelectedListener Override onImageSelected

@Override
public void onImageSelected(int groupPos){
    if(expandableList.isGroupExpanded(groupPos)){
        expandableList.collapseGroup(groupPos);
    }else{
        expandableList.expandGroup(groupPos);
    }
}

Answer 2

更简单的方法：

将引用传递给适配器构造函数中的ExpandableListView;
在getGroupView中为您需要的按钮添加OnClickListener，只需致电listView.expandGroup(position);

示例：

public class YourAdapter extends BaseExpandableListAdapter {

private ExpandableListView listView;

public ReportsAdapter(ExpandableListView listView) {
    this.listView = listView;
}

//...

@Override
public View getGroupView(final int position, boolean isExpanded, View convertView, ViewGroup parent) {
    ParentViewHolder holder;

    if (convertView == null) {
        convertView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.your_item, parent, false);

        holder = new ParentViewHolder();

        //... holder logic


        holder.btnExpand = convertView.findViewById(R.id.btn_expand);

        convertView.setTag(holder);
    } else {
        holder = (ParentViewHolder) convertView.getTag();
    }

    //..holder logic

    holder.btnExpand.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            listView.expandGroup(position);
        }
    });

    return convertView;
}

在您的活动onCreate()或片段onCreateView()中

ExpandableListView listView = (ExpandableListView) view.findViewById(R.id.expandable_list_view);
    mAdapter = new YourAdapter(listView);
    listView.setAdapter(mAdapter);

Answer 3

这不会回答OP中的问题，但是我最终在这里找到了一种方法，只有在适配器加载了项目之后，才能以编程方式扩展组，这是我的解决方法：

MyAdapter adapter = new MyAdapter(this, viewModel);

adapter.registerDataSetObserver(new DataSetObserver() {
     @Override
     public void onChanged() {
          super.onChanged();
          if (adapter.getGroupCount()>0) {
               binding.expandableListView.expandGroup(0);
          }
        }
    });
binding.expandableListView.setAdapter(adapter);

在可扩展列表中以编程方式展开组行

3 个答案: