如何在所有组的第一个孩子上设置 ImageView.VISIBLE，其他 ChildViews 应该隐藏在 ExpandableListView

Question

实现了 ExpandableListview，我在 childView 上有 ImageView，它应该在组的第一个孩子上是 VISIBLE 并且对于其他 ChildView 应该是 Hidden 并且在重新加载 listView 后如何我持有 childView 的 Image 状态。

找到下面我实现的代码

filterChild.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <TextView
        android:id="@+id/lblListItemFilter"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:paddingLeft="?android:attr/expandableListPreferredChildPaddingLeft"
        android:paddingTop="10dp"
        android:paddingBottom="10dp"
        android:focusable="false"
        android:descendantFocusability="blocksDescendants"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/check"
        android:layout_width="15dp"
        android:layout_height="15dp"
        android:layout_gravity="left"
        android:layout_marginEnd="16dp"
        android:background="@drawable/checkmark"
        android:gravity="center"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

活动中的侦听器

expListView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {

            @Override
            public boolean onGroupClick(ExpandableListView parent, View v,
                                        int groupPosition, long id) {
                 Toast.makeText(getApplicationContext(),
                 "Group Clicked " + listDataHeader.get(groupPosition),
                 Toast.LENGTH_SHORT).show();

                return false;
            }
        });

        expListView.setOnGroupExpandListener(new ExpandableListView.OnGroupExpandListener() {

            @Override
            public void onGroupExpand(int groupPosition) {
                Toast.makeText(getApplicationContext(),
                        listDataHeader.get(groupPosition) + " Expanded",
                        Toast.LENGTH_SHORT).show();
            }
        });


        expListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {

            @Override
            public boolean onChildClick(ExpandableListView parent, View v,
                                        int groupPosition, int childPosition, long id) {
                // TODO Auto-generated method stub
               System.out.println("childPosition"+listDataChild.get(
                       listDataHeader.get(groupPosition)).get(
                       childPosition));

                Toast.makeText(
                        getApplicationContext(),
                        listDataHeader.get(groupPosition)
                                + " : "
                                + listDataChild.get(
                                listDataHeader.get(groupPosition)).get(
                                childPosition), Toast.LENGTH_SHORT)
                        .show();
                return true;
            }
        });

BaseExpandableListAdapter 类

package com.conduent.conduentebi;

import android.content.Context;
import android.graphics.Typeface;
import android.icu.util.ULocale;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.HashMap;
import java.util.List;

public class FilterExpandableListAdapter extends BaseExpandableListAdapter {

    private Context _context;
    private List<String> _listDataHeader; // header titles
    // child data in format of header title, child title
    private HashMap<String, List<String>> _listDataChild;

    private HashMap<Integer, boolean[]> mChildCheckStates;
    private List<ULocale.Category> mGroupCollection;

    public FilterExpandableListAdapter(Context context, List<String> listDataHeader,
                                 HashMap<String, List<String>> listChildData) {
        this._context = context;
        this._listDataHeader = listDataHeader;
        this._listDataChild = listChildData;

        mChildCheckStates = new HashMap<Integer, boolean[]>();
    }

    @Override
    public Object getChild(int groupPosition, int childPosititon) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .get(childPosititon);
    }

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

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

        final int mGroupPosition = groupPosition;
        final int mChildPosition = childPosition;

        ChildViewHolder viewHolder = null;

        final String childText = (String) getChild(groupPosition, childPosition);

        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.filter_child, null);

            System.out.println("mChildPosition"+mChildPosition);

                viewHolder = new ChildViewHolder();

//                viewHolder.checkBox1 = (CheckBox) convertView.findViewById(R.id.check);
//                viewHolder.checkBox1.setFocusable(false);

                viewHolder.mChildText = (TextView) convertView
                        .findViewById(R.id.lblListItemFilter);

                //viewHolder.checkBox1 = (CheckBox)convertView.findViewById(R.id.check);

                convertView.setTag(R.layout.filter_child, viewHolder);
                //viewHolder.checkBox2 = (CheckBox)convertView.findViewById(R.id.check);

        }else {
            viewHolder = (ChildViewHolder) convertView
                    .getTag(R.layout.filter_child);
        }

       // TextView txtListChild = (TextView) convertView
         //       .findViewById(R.id.lblListItemFilter);

        viewHolder.mChildText.setText(childText);




        convertView.setClickable(false);

        return convertView;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .size();
    }





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

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

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

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



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

        convertView.setClickable(false);

        return convertView;
    }

    class ChildViewHolder{

        TextView mChildText;
        ImageView checkBox1;

    }

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

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

Answer 1

如果您想保持视图的旧状态并在重新加载屏幕时相应地显示视图，我建议您构建一个模型来保存您的数据并列出它。

对于任何更改，您都应该使用该模型的列表来更新数据。这将帮助您维护列表项中不同视图的状态。