Question

我为儿童用品设计了ExpandableListView CheckedTextView，但每件事情都很好但是当我随机检查其他组中的CheckedTextView随机CheckedTextView时 check.this ExpandableListView让我疯了。这是我的代码

   public class ExpandableListAdapter extends BaseExpandableListAdapter {

private Context context;
private List<String> expandableListTitle;
private HashMap<String, List<String>> expandableListDetail;   
public int lastExpandedGroupPosition;    

public ExpandableListAdapter(Context context, List<String> expandableListTitle,
        HashMap<String, List<String>> expandableListDetail) {
    this.context = context;
    this.expandableListTitle = expandableListTitle;
    this.expandableListDetail = expandableListDetail;      
}
@Override
//counts the number of group/parent items so the list knows how many times calls getGroupView() method
public int getGroupCount() {
     return this.expandableListTitle.size();
}

@Override
//counts the number of children items so the list knows how many times calls getChildView() 
method
public int getChildrenCount(int listPosition) {
    return this.expandableListDetail.get(this.expandableListTitle.get(listPosition))
            .size();     
}

@Override
//gets the title of each parent/group
public Object getGroup(int listPosition) {      
     return this.expandableListTitle.get(listPosition);
}

@Override
//gets the name of each item
public Object getChild(int listPosition, int expandedListPosition) {
    return this.expandableListDetail.get(this.expandableListTitle.get(listPosition))
            .get(expandedListPosition);    
}

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

@Override
public long getChildId(int listPosition, int expandedListPosition) {
    return expandedListPosition;
}

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

@Override
//in this method you must set the text to see the parent/group on the list
public View getGroupView(int listPosition, boolean isExpanded, View convertView, ViewGroup 
parent) {
 String listTitle = (String) getGroup(listPosition);
    if (convertView == null) {
        LayoutInflater layoutInflater = (LayoutInflater) this.context.
                getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = layoutInflater.inflate(R.layout.list_group, null);
    }
    // set category name as tag so view can be found view later
    convertView.setTag(getGroup(listPosition).toString());

    TextView textView = (TextView) convertView.findViewById(R.id.listTitle);

    //"i" is the position of the parent/group in the list
    textView.setText(getGroup(listPosition).toString());

    TextView sub = (TextView) convertView.findViewById(R.id.list_item_text_subscriptions);      


    return convertView;
}


 @Override
 //in this method you must set the text to see the children on the list
 public View getChildView(int listPosition, int expandedListPosition, boolean isLastChild, View
 convertView, ViewGroup parent) {
     final String expandedListText = (String) getChild(listPosition, expandedListPosition);
     if (convertView == null) {
         LayoutInflater layoutInflater = (LayoutInflater) this.context
                 .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         convertView = layoutInflater.inflate(R.layout.list_item, null);
     }

    CheckedTextView textView = (CheckedTextView)
   convertView.findViewById(R.id.list_item_text_child);       
    textView.setText(expandedListText);  
    return convertView;
}

@Override
public boolean isChildSelectable(int listPosition, int expandedListPosition) {
    return true;
}

}

这是来自json回复的数据

public class ExpandableListDataPump {

public static HashMap<String, List<String>> getData() {

    ServiceHandler sh = new ServiceHandler();
    String url = "http://****/**/fetch_details/services/news_keywords.json";
    // Making a request to url and getting response
    String jsonStr = sh.makeServiceCall(url, ServiceHandler.POST);

    ArrayList<HashMap<String, String>> dataHashMap = new ArrayList<HashMap<String, String>>();

    try {
        JSONArray jsonArray = new JSONArray(jsonStr);

        for (int i = 0; i < jsonArray.length(); i++) {
            JSONObject c = jsonArray.getJSONObject(i);
            HashMap<String, String> dataArray = new HashMap<String, String>();
            if(!c.isNull("name")){                  
            String region = c.getString("name");
            String state = c.getString("ank_name");
            dataArray.put("name", region);
            dataArray.put("ank_name", state);               
            dataHashMap.add(dataArray);

            }
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }

    HashMap<String, List<String>> expandableListDetail = new HashMap<String, List<String>>();
    Set<String> regionsList = new HashSet<String>();

    for (HashMap<String, String> map : dataHashMap) {
        for (Entry<String, String> mapEntry : map.entrySet()) {
            String key = mapEntry.getKey();
            String value = mapEntry.getValue();
            if (key.equalsIgnoreCase("name")) {

                regionsList.add(value);

            }

        }
    }
    try {
        JSONArray jsonArray = new JSONArray(jsonStr);

        for (String regionName : regionsList) {
            Log.e("Keywords list", regionName);

            List<String> name = new ArrayList<String>();
            for (int i = 0; i < jsonArray.length(); i++) {
                JSONObject c = jsonArray.getJSONObject(i);
                String regionTemp = c.getString("name");
                String nameTemp = c.getString("ank_name");
                if (regionTemp.equalsIgnoreCase(regionName)) {
                    name.add(nameTemp);
                }
            }
            expandableListDetail.put(regionName, name);

        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
    return expandableListDetail;
  }
 }

是list_group.xml就是这个

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
    android:id="@+id/listTitle"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:paddingLeft="?android:attr/expandableListPreferredItemPaddingLeft"
    android:textColor="#A4C739"
    android:paddingTop="10dp"
    android:paddingBottom="10dp" />
</LinearLayout>

list_item.xml就是这个

 <?xml version="1.0" encoding="utf-8"?>

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical" android:layout_width="match_parent"
 android:layout_height="wrap_content">

  <CheckedTextView
    android:id="@+id/list_item_text_child"
    android:layout_width="match_parent"
    android:layout_height="?android:attr/listPreferredItemHeightSmall"
    android:textAppearance="?android:attr/textAppearanceListItemSmall"
    android:gravity="center_vertical"
    android:textSize="15sp"
    android:checkMark="?android:attr/textCheckMark"
    android:paddingStart="?android:attr/listPreferredItemPaddingStart"
    android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"

   />

 </LinearLayout>

Answer 1

每当滚动ListView / ExpandableListView时，它都会调用＆＃34; getView＆＃34;滚动时相应适配器在运行时的功能。假设您在ListView中有10个项目，其中前5个项目当前正在屏幕上显示。此时，ListView已调用＆＃34; getView＆＃34;仅适用于当前显示的项目。现在，当您将列表向上滚动时，它将开始调用＆＃34; getView＆＃34;适配器逐一适用于第6，第7，第8 ......项目。

另一方面，CheckedTextView将其检查状态设置为默认值（如果未在布局XML中设置，则为FALSE）。所以每当ListView调用＆＃34; getView＆＃34;适配器，它为该项创建一个新的布局，并根据新的布局，CheckedTextView的检查状态返回到DEFAULT。

要处理此问题，您必须保存每个CheckedTextView的Checked-State，并将此值设置为CheckedTextView，同时从＆＃34; getView＆＃34;返回视图。适配器。

编辑：

在ExpandableListAdapter的构造函数中，使用默认的检查状态值填充以下数组列表...

ArrayList<ArrayList<Boolean>> checkStates = new ArrayList<ArrayList<Boolean>>();

public void MyExpendableListAdapter()
{
       checkStates = new ArrayList<ArrayList<Boolean>>();
       //
       for(int i=0; i<numberOfGroups; i++) // Number of total groups or headers
       {
              ArrayList<Boolean> childrenCheckedStates = new ArrayList<Boolean>();
              for(int j=0; j<groups.get(i).size(); j++) // saving checked state for each children in each group
              {
                     childrenCheckedStates.add(defaultCheckState); // true or false
              }
              checkStates.add(childrenCheckedStates);
       }
}

现在在getChildView ...

public View getChildView(final int listPosition, final int expandedListPosition,
        boolean isLastChild, View convertView, ViewGroup parent) {
    final String expandedListText = (String) getChild(listPosition,
            expandedListPosition);
    if (convertView == null) {
        LayoutInflater layoutInflater = (LayoutInflater) this.context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = layoutInflater.inflate(R.layout.list_item, null);
    }

    CheckedTextView textView = (CheckedTextView) convertView
            .findViewById(R.id.list_item_text_child);

    textView.setText(expandedListText);

    textView.setChecked(checkStates.get(listPosition).get(expandedListPosition));

    textView.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            CheckedTextView tv = (CheckedTextView)v;
            checkStates.get(listPosition).set(expandedListPosition, tv.isChecked());
        }
    });

    return convertView;
}

祝你好运。：）

Answer 2

我遇到过这个问题。实际上我们必须管理它。

我使用了以下方法

将已检查的子索引添加到列表

在getchildView中

，如果选中，请检查checkedtextview。

((CheckedTextView) convertView).setChecked(getClicked(
                        groupPosition, childPosition));

下面的函数将返回一个布尔值，无论是否检查给定的子项

public boolean getClicked(int groupPosition, int childPosition) {
    if (checkedPositions.get(groupPosition) != null) {
        boolean isChecked = checkedPositions.get(groupPosition).get(
                childPosition);
        return isChecked;
    }
    return false;
}

您可以使用这样的函数来索引已检查的项目

public void setClicked(int groupPosition, int childPosition) {

SparseBooleanArray checkedChildPositionsSingle = checkedPositions
        .get(groupPosition);
if (checkedChildPositionsSingle == null) {
    checkedChildPositionsSingle = new SparseBooleanArray();
    checkedChildPositionsSingle.put(childPosition, true);
    checkedPositions.put(groupPosition, checkedChildPositionsSingle);
} else {
    boolean oldState = checkedChildPositionsSingle.get(childPosition);
    if (!oldState) {
        checkedChildPositionsSingle.clear();
        checkedChildPositionsSingle.put(childPosition, !oldState);
    }
}
notifyDataSetChanged();

}

补充：

 @Override
 //in this method you must set the text to see the children on the list
 public View getChildView(int listPosition, int expandedListPosition, boolean isLastChild, View
 convertView, ViewGroup parent) {
     final String expandedListText = (String) getChild(listPosition, expandedListPosition);
     if (convertView == null) {
         LayoutInflater layoutInflater = (LayoutInflater) this.context
                 .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         convertView = layoutInflater.inflate(R.layout.list_item, null);
     }

    CheckedTextView textView = (CheckedTextView)
   convertView.findViewById(R.id.list_item_text_child);       
    textView.setText(expandedListText);  
((CheckedTextView) convertView).setChecked(getClicked(
                            groupPosition, childPosition)); //Added
    return convertView;

}

在创建适配器的类中创建onChildClickListener

expandableListView.setOnChildClickListener(new OnChildClickListener() {
                        @Override
                        public boolean onChildClick(ExpandableListView parent,
                                View clickedView, int groupPosition,
                                int childPosition, long id) {
                    expandableListAdapter.setClicked(groupPosition,childPosition);
            }
        }

注意：checkedPositions是SparseBooleanArray

的数组

SparseArray<SparseBooleanArray> checkedPositions;

检查checkedtextview后滚动时，checkedtextview会被随机选中并取消选中

2 个答案: