ExpandableListView，如何将 child 范围最小值限制为 1 [如果没有项目则为 0]

Question

我想在 ExpandableListView 的折叠状态下显示一个 child（在没有项目的情况下为 0）。 Android 给出 collapseGroup 但它折叠了所有项目。除了一个元素外，我想折叠 child。

任何线索或帮助将不胜感激。

Answer 1

如果 ExpandableListView 子组在 collapseGroup 上折叠时显示一个项目（如果为空则为 null）而不是 none 必须实现他的自己的 ExpandableListView 与自定义 ExpandableListConnector 实现相关，使用 "overriden" collapseGroup 和 expandGroup 方法。例如 collapseGroup 必须是：

 boolean collapseGroup(int groupPos) {
     ExpandableListPosition elGroupPos = ExpandableListPosition.obtain(
             ExpandableListPosition.GROUP, groupPos, -1, -1);
     PositionMetadata pm = getFlattenedPos(elGroupPos);
     elGroupPos.recycle();
     // Group will be collapsed until there will be presented 1 or null items
     if (pm == null && mExpGroupMetadataList.size() <= 1) return false;

     boolean retValue = collapseGroup(pm);
     pm.recycle();
     return retValue;
 }

 boolean collapseGroup(PositionMetadata posMetadata) {
     /*
      * Collapsing requires removal from mExpGroupMetadataList 
      */

     /*
      * If it is null, it must be already collapsed. This group metadata
      * object should have been set from the search that returned the
      * position metadata object.
      */
     // Group will be collapsed until there will be presented 1 or null items
     if (posMetadata.groupMetadata == null && mExpGroupMetadataList.size() <= 1) return false;

     // Remove the group from the list of expanded groups 
     mExpGroupMetadataList.remove(posMetadata.groupMetadata);

     // Refresh the metadata
     refreshExpGroupMetadataList(false, false);

     // Notify of change
     notifyDataSetChanged();

     // Give the callback
     mExpandableListAdapter.onGroupCollapsed(posMetadata.groupMetadata.gPos);

     return true;
 }

必须为 expandGroup 实施类似的逻辑。

ExpandableListView，如何将 child 范围最小值限制为 1 [如果没有项目则为 0]

ExpandableListView, how to limit the child range minimum to 1 [0 in case of no item]

android

android-layout