ExpandableListView打开折叠问题

Question

我正在使用自定义可扩展列表适配器。当用户单击某个子项时，我会突出显示该子项。在用户打开/折叠组之前，这一切正常。假设用户触摸组 2 项目 1。这将突出显示组 2 项目 1。然后用户打开组 1。现在突出显示组 3 项目 2。我已经做了一些选择不同项目的测试，但找不到突出显示的行将跳转到的模式。有时它在列表中向上，有时它在列表中向下。我无法弄清楚放入活动的

onGroupExpandListener

和

onGroupCollapseListener

以重新突出显示正确视图的逻辑。有什么想法吗？

编辑：我的 onChildClickListener 中的当前代码

if (groupPosition == 0){ 
      switch(childPosition) {
      case 0: 
        previouslySelectedView.setBackgroundResource(R.color.transparent);
        currentlySelectedView.setBackgroundResource(R.color.blue); 
        break;

所有团体/儿童使用相同的代码

Answer 1

ExpandableListView 中的项目选择是通过平面列表（绝对定位）进行的。因此，如果新打开的组位于当前选择之前并且具有较少的子组，则选择将向上移动，反之亦然。我建议将选择模式设置为 none 并实现 onclick/expand 逻辑来处理您自己的焦点 - 例如，为视图实现标签，并通过标签设置当前突出显示的项目。

以下是一些建议：

我目前正在使用列表的选择模式倍数进行 ExpandableListView 选择。但正如我所说，由于选择是按位置进行的，因此我必须在功能方面做出牺牲 - 即，每当进行操作时我都会清除选择。之前的实现是使用自定义 Map 来保存选定的 ID，老实说，这是更好的方法。

这就是我获取选定 ID 的方法（记住我使用多重选择模式）：

final SparseBooleanArray checkedPositions = expList.getCheckedItemPositions();
final ExpandableListAdapter adapter = expList.getExpandableListAdapter();
List<Long> checkedIds = new ArrayList<Long>();
if (packedPositionType == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {
    for (int i = checkedPositions.size() - 1; i >= 0; i--) {
        if (checkedPositions.valueAt(i)) {
            checkedIds.add(adapter.getGroupId(checkedPositions.keyAt(i)));
        }
    }
}

不过，就您而言，您需要检查是否有儿童挤满的位置。另请注意，我的适配器具有稳定（唯一）的 ID。如果您没有稳定的 ID，那么您可以依靠 ExpandableListView 的 getPackedPositionForChild() 方法并将打包位置存储为标记。

Answer 2

正确的做法（将解决组崩溃时突出显示的跳跃问题）

在 ExpandableListView 上执行以下操作：

步骤 1. 将选择模式设置为单一（可以在 xml 中完成，如 android:choiceMode = "singleChoice"）

步骤 2. 使用选择器 xml 作为背景 (android:listSelector = "@drawable/selector_list_item")

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android"
   android:exitFadeDuration="@android:integer/config_mediumAnimTime">

   <item android:drawable="@android:color/holo_blue_bright" android:state_pressed="true"/>
   <item android:drawable="@android:color/holo_blue_light" android:state_selected="true"/>
   <item android:drawable="@android:color/holo_blue_dark" android:state_activated="true"/>

</selector>

第3步。在onChildClick()回调中调用expandableListView.setItemChecked(index,true)。

index 是子项的从 0 开始的索引，计算如下

第 1 组 [索引 = 0]

第 2 组 [索引 = 4]

第 3 组 [索引 = 8]

如果我们也有列表标题，它们也会考虑索引值。

这是一个工作示例：

@Override
public boolean onChildClick(ExpandableListView parent, View v,
        int groupPosition, int childPosition, long id) {
    ...

    int index = parent.getFlatListPosition(ExpandableListView.getPackedPositionForChild(groupPosition, childPosition));
    parent.setItemChecked(index, true);


    return true;
}

Answer 3

我对崩溃问题的解决方案：

mDrawerExpandableList.setOnGroupCollapseListener(new OnGroupCollapseListener() {
    @Override
    public void onGroupCollapse(int groupPosition) {
        if(ExpandableListView.getPackedPositionGroup(selectedFragmentId) == groupPosition) {
            mDrawerExpandableList.setItemChecked(mDrawerExpandableList.getFlatListPosition(ExpandableListView.getPackedPositionForGroup(groupPosition)), true);
        }
    }
});
mDrawerExpandableList.setOnGroupExpandListener(new OnGroupExpandListener() {
    @Override
    public void onGroupExpand(int groupPosition) {
        if(ExpandableListView.getPackedPositionGroup(selectedFragmentId) == groupPosition) {
            mDrawerExpandableList.setItemChecked(((ExpandableListView)drawerListView).getFlatListPosition(selectedFragmentId), true);
        }
    }
});

Answer 4

//MY LIST A FOLLOWS



(0)SALES
    (0)SALES
    (1)SALES VIEW
    (2)SALES RETURN
    (3)SALES RETURN VIEW
(1)STOCK
    (0)ADD STOCK
    (1)VIEW STOCK
(2)SETTINGS
(3)NOTIFICATION



//declare tow integer variable globali as follows

private int lastCheckedGroupPosition=-1;
private int lastCheckedChildPosition=-1;


mDrawerList.setOnGroupClickListener(new OnGroupClickListener() {

        @Override
        public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) {
            if(groupPosition==2){
                lastCheckedGroupPosition=groupPosition;
                lastCheckedChildPosition=-1;
                int index = parent.getFlatListPosition(ExpandableListView.getPackedPositionForGroup(groupPosition));
                parent.setItemChecked(index, true);

                //TODO Write here the code for opening settings page
                ...............
                ...............
                ...............
                return true;
            }
            else if(groupPosition==3){
                lastCheckedGroupPosition=groupPosition;
                lastCheckedChildPosition=-1;
                int index = parent.getFlatListPosition(ExpandableListView.getPackedPositionForGroup(groupPosition));
                parent.setItemChecked(index, true);             

                //TODO Write here the code for opening settings page
                ...............
                ...............
                ...............

                return true;
            }
            return false;               
        }
    });
    mDrawerList.setOnChildClickListener(new OnChildClickListener() {

        @Override
        public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
            if(groupPosition==0){
                if(childPosition==0){
                    //TODO Write here the code for opening SALES page
                    ...............
                    ...............
                    ...............                     
                }
                else if(childPosition==1){
                    //TODO Write here the code for opening SALES VIEW page
                    ...............
                    ...............
                    ...............                     
                }
                else if(childPosition==2){
                    //TODO Write here the code for opening SALES RETURN page
                    ...............
                    ...............
                    ...............                     
                }
                else if(childPosition==3){
                    //TODO Write here the code for opening SALES RETURN VIEW page
                    ...............
                    ...............
                    ...............                     
                }
            }
            else if(groupPosition==1){
                if(childPosition==0){
                    //TODO Write here the code for opening ADD STOCK page
                    ...............
                    ...............
                    ...............                     
                }
                else if(childPosition==1){
                    //TODO Write here the code for opening VIEW STOCK page
                    ...............
                    ...............
                    ...............                     
                }
            }
            int index = parent.getFlatListPosition(ExpandableListView.getPackedPositionForChild(groupPosition, childPosition));
            parent.setItemChecked(index, true);
            lastCheckedGroupPosition=groupPosition;
            lastCheckedChildPosition=childPosition;
            return false;
        }
    });
    mDrawerList.setOnGroupExpandListener(new OnGroupExpandListener() {

        @Override
        public void onGroupExpand(int groupPosition) {
            if(groupPosition==lastCheckedGroupPosition){
                if(lastCheckedChildPosition!=-1){
                    int index = mDrawerList.getFlatListPosition(ExpandableListView.getPackedPositionForChild(lastCheckedGroupPosition, lastCheckedChildPosition));
                    mDrawerList.setItemChecked(index, true);                            
                }
                else{
                    int index = mDrawerList.getFlatListPosition(ExpandableListView.getPackedPositionForGroup(lastCheckedGroupPosition));    
                    mDrawerList.setItemChecked(index, true);                            
                }
            }
            else{
                if(mDrawerList.isGroupExpanded(lastCheckedGroupPosition)){
                    if(lastCheckedChildPosition!=-1){
                        int index = mDrawerList.getFlatListPosition(ExpandableListView.getPackedPositionForChild(lastCheckedGroupPosition, lastCheckedChildPosition));
                        mDrawerList.setItemChecked(index, true);                            
                    }
                    else{
                        int index = mDrawerList.getFlatListPosition(ExpandableListView.getPackedPositionForGroup(lastCheckedGroupPosition));    
                        mDrawerList.setItemChecked(index, true);                            
                    }
                }
                else{
                    mDrawerList.setItemChecked(-1, true);
                }
            }


        }
    });
    mDrawerList.setOnGroupCollapseListener(new OnGroupCollapseListener() {

        @Override
        public void onGroupCollapse(int groupPosition) {

            if(groupPosition==lastCheckedGroupPosition){
                if(lastCheckedGroupPosition!=-1){
                    int index = mDrawerList.getFlatListPosition(ExpandableListView.getPackedPositionForGroup(lastCheckedGroupPosition));    
                    mDrawerList.setItemChecked(index, true);    
                }
                else{
                    mDrawerList.setItemChecked(-1, true);
                }
            }
            if(mDrawerList.isGroupExpanded(lastCheckedGroupPosition)){
                if(lastCheckedChildPosition!=-1){
                    int index = mDrawerList.getFlatListPosition(ExpandableListView.getPackedPositionForChild(lastCheckedGroupPosition, lastCheckedChildPosition));
                    mDrawerList.setItemChecked(index, true);                            
                }
                else{
                    int index = mDrawerList.getFlatListPosition(ExpandableListView.getPackedPositionForGroup(lastCheckedGroupPosition));    
                    mDrawerList.setItemChecked(index, true);                            
                }
            }
            else{
                mDrawerList.setItemChecked(-1, true);
            }

        }
    });

Answer 5

我通过在

checkedGroupPosition

和

checkedChildPosition

中记录选中的组位置和子位置并更新

#onGroupExpand

和

#onGroupCollapse

中选中的项目来解决它：

override fun onGroupExpand(groupPosition: Int) {
    // Re-check the previous checked item because the flat position may have changed.
    updateCheckedItem()
  }

  override fun onGroupCollapse(groupPosition: Int) {
    // Re-check the previous checked item because the flat position may have changed.
    updateCheckedItem()
  }

  private fun updateCheckedItem() {
    // Checked item is a child item.
    if (checkedGroupPosition > -1 && checkedChildPosition > -1) {
      if (expandableListView.isGroupExpanded(checkedGroupPosition)) {
        // Check the item again if the group is expanded.
        expandableListView.setItemChecked(
          expandableListView.getFlatListPosition(
            ExpandableListView.getPackedPositionForChild(checkedGroupPosition, checkedChildPosition)
          ),
          true,
        )
      } else {
        // Clear the checked item if its group is collapsed.
        expandableListView.setItemChecked(-1, true)
      }
      return
    }
    // Checked item is a group item, check the item again.
    if (checkedGroupPosition > -1) {
      expandableListView.setItemChecked(
        expandableListView.getFlatListPosition(
          ExpandableListView.getPackedPositionForGroup(checkedGroupPosition)
        ),
        true,
      )
    }
  }

ExpandableListView打开折叠问题

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