android - 如何用两个不同的对象填充 ExpandableListView

Question

我有一个可扩展 ListView ，想用两个不同的对象填充它，目前我只是用 Tareas 对象填充子项，但想用不同的对象 (Metas) 填充同一个子项列表。我怎样才能做到这一点，因为我的适配器只是用 Tareas 对象填充列表，而不是接受 Metas 对象。

UPDATE

这是我的 ExpandableListViewAdapter:

public class CalendarioAdapter extends BaseExpandableListAdapter {
private Context mContext;
private List<String> mCalendarioListHeader;
private HashMap<String, List<Object>> mCalendarioListChild;
private static final int CHILD_TYPE_META = 0;
private static final int CHILD_TYPE_PLANES = 1;


public CalendarioAdapter(Context context, List<String> listDataHeader,
                         HashMap<String, List<Object>> listChildData) {
    this.mContext= context;
    this.mCalendarioListHeader= listDataHeader;
    this.mCalendarioListChild = listChildData;
}
@Override
public int getChildTypeCount() {
    return 2;
}


@Override
public int getGroupCount() {
    return this.mCalendarioListHeader.size();
}

@Override
public int getChildrenCount(int groupPosition) {
    List childList = mCalendarioListChild.get(mCalendarioListHeader.get(groupPosition));
    if (childList != null && ! childList.isEmpty()) {
        return childList.size();
    }
    return 0;
}


@Override
public Object getGroup(int groupPosition) {
    return this.mCalendarioListHeader.get(groupPosition);
}

@Override
public Object getChild(int groupPosition, int childPosition) {
    return this.mCalendarioListChild.get(this.mCalendarioListHeader.get(groupPosition))
            .get(childPosition);
}

@Override
public long getGroupId(int groupPosition) {
    return groupPosition;
}

@Override
public long getChildId(int groupPosition, int childPosition) {
    return childPosition;
}

@Override
public boolean hasStableIds() {
    return false;
}

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
    String headerTitle = (String) getGroup(groupPosition);
    String listSize = getChildrenCount(groupPosition) +"";
    if (convertView == null) {
        LayoutInflater infalInflater = (LayoutInflater) this.mContext
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = infalInflater.inflate(R.layout.calendario_list_header, null);
    }

    TextView lblListHeader = (TextView) convertView
            .findViewById(R.id.lblListHeader);
    TextView sizeOfList = (TextView) convertView.findViewById(R.id.calendarioListSize);
    sizeOfList.setText(listSize);
    lblListHeader.setTypeface(null, Typeface.BOLD);
    lblListHeader.setText(headerTitle);

    return convertView;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {


    Integer childType = (getChildType(groupPosition, childPosition));
    Log.d("childType", childType+"");

    LayoutInflater layoutInflater = (LayoutInflater) this.mContext
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    if (convertView == null|| convertView.getTag() != childType) {

        switch (childType) {

            case CHILD_TYPE_META:
                convertView = layoutInflater.inflate(R.layout.metas_list_row, null);
                convertView.setTag(childType);
                break;
            case CHILD_TYPE_PLANES:
                convertView =  layoutInflater.inflate(R.layout.calendario_list_row, null);
                convertView.setTag(childType);
                break;
            default:

                break;
        }
    }
    switch (childType) {
        case CHILD_TYPE_META:
            Metas metas = (Metas) getChild(groupPosition, childPosition);
            TextView txtMetasChild =  convertView.findViewById(R.id.metasTxtChild);
            TextView fechaMetasChild = convertView.findViewById(R.id.fechaMetaChild);
            txtMetasChild.setText(metas.getMeta());
            fechaMetasChild.setText(metas.getFecha());
            break;
        case CHILD_TYPE_PLANES:
            Tareas tareas = (Tareas) getChild(groupPosition, childPosition);
            TextView txtDescripcionChild = (TextView) convertView
                    .findViewById(R.id.descripcionTareaText);
            TextView txtListaChild = (TextView) convertView
                    .findViewById(R.id.listaTareaText);
            txtDescripcionChild.setText(tareas.getDescripcion());
            txtListaChild.setText(tareas.getLista());
            break;

        default:
            break;
    }

    return convertView;


  }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

    @Override
    public int getChildType(int groupPosition, int childPosition) {
        Object child = getChild(groupPosition, childPosition);
        Log.d("ChildType", child+"");
        if(child instanceof Metas){
            return CHILD_TYPE_META;
        } else if(child instanceof Tareas) {
            return CHILD_TYPE_PLANES;
        }
        else{
// should never happen, so do error handling here
            throw new RuntimeException("only classes Metas and Tareas permitted");
        }
    }
}

And on my Fragment I populate the list like this:

       private void prepareListData() {
        listDataHeader = new ArrayList<String>();
        listDataChild = new HashMap<String, List<Object>>();

        // Adding header data
        listDataHeader.add(diasText[0]);
        listDataHeader.add(diasText[1]);
        listDataHeader.add(diasText[2]);
        listDataHeader.add(diasText[3]);
        listDataHeader.add(diasText[4]);
        listDataHeader.add(diasText[5]);
        listDataHeader.add(diasText[6]);

        // Adding child data

        listDataChild.put(listDataHeader.get(0), dia1List);
        listDataChild.put(listDataHeader.get(1), dia2List);
        listDataChild.put(listDataHeader.get(2), dia3List);
        listDataChild.put(listDataHeader.get(3), dia4List);
        listDataChild.put(listDataHeader.get(4), dia5List);
        listDataChild.put(listDataHeader.get(5), dia6List);
        listDataChild.put(listDataHeader.get(6), dia7List);
    }

任何关于如何实现我的要求的想法都将不胜感激!

Answer 1

子类化时 BaseExpandableListAdapter , 你可以提供不同的 View组项目和子项目的类型。我只会概述如何做不同的 child View types 因为那是你想要做的(即便如此，帖子也会变得足够长)。

View类型由 int 表示值，例如

private static final int TYPE_TAREAS = 0;
private static final int TYPE_METAS = 2;

所以在你的情况下你传递了一个 HashMap<String, List<Object>>而不是 HashMap<String, List<Tareas>>并覆盖 getChildTypeCount()返回 2(不同 View 类型的数量)。 (当然你也可以使用 Tareas 和 Metas 的任何共同祖先来代替 Object )

然后你覆盖getChildType (int groupPosition, int childPosition)返回正确的 int View 的值(TYPE_TAREAS 或 TYPE_METAS)键入此特定条目。要确定类型，请使用 instanceof在 List 上条目。

最后，当覆盖 getChildView() 时, 你在 List 上做必要的类型转换输入并确定 View通过调用 getChildType() 输入.一如既往ListView ，您可以重用convertView。

这是 documentation for getChildView() 的内容在这个话题上说:

convertView View: the old view to reuse, if possible. You should check that this view is non-null and of an appropriate type before using. If it is not possible to convert this view to display the correct data, this method can create a new view. It is not guaranteed that the convertView will have been previously created by getChildView(int, int, boolean, View, ViewGroup).

如果 convertView 不能被重用，你创建一个新的 View根据View通过膨胀所需的布局来键入。遵循 ViewHolder 模式是个好主意。您可能需要两个完全不同的 ViewHolder 或一个从另一个扩展，这取决于您的两个数据类之间的差异。

其余一切如常:-)