Java+Kotlin混合调用实现时光轴（ExpandableListView可扩展列表）

效果图：

主布局xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#f7f7f7" >

    <RelativeLayout
        android:id="@+id/date_layout"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="10dp"
        android:paddingTop="10dp" >

        <TextView
            android:id="@+id/time_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:text="2014年10月"
            android:textColor="@android:color/black" />
    </RelativeLayout>

    <View
        android:id="@+id/top_line"
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:layout_below="@id/date_layout"
        android:background="@color/head_line_bg" />

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_below="@id/top_line" >

        <View
            android:id="@+id/group_tiao"
            android:layout_width="1dp"
            android:layout_height="fill_parent"
            android:layout_marginLeft="55dp"
            android:background="@color/time_line_bg" />

        <TextView
            android:id="@+id/courses_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="10dp"
            android:layout_marginLeft="70dp"
            android:layout_marginTop="10dp"
            android:text="时光轴"
            android:textColor="@android:color/black"
            android:textSize="22dp" />

        <ExpandableListView
            android:id="@+id/expandlist"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_below="@+id/courses_title"
            android:cacheColorHint="#00000000"
            android:divider="@null" />
    </RelativeLayout>

</RelativeLayout>

item布局child_status_item

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_vertical" >

    <TextView
        android:id="@+id/two_complete_time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="6dp"
        android:layout_marginLeft="70dp"
        android:layout_marginTop="6dp"
        android:textColor="#999999" />

</LinearLayout>

item布局group_status_item

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_vertical" >

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="20dp"
        android:layout_height="20dp"
        android:layout_gravity="center_vertical"
        android:layout_marginLeft="45dp"
        android:layout_marginRight="5dp"
        android:background="@drawable/icons_ok"
        android:contentDescription="@string/app_name" />

    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="20dip"
        android:layout_marginTop="20dp"
        android:gravity="center_vertical"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/one_status_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/app_name"
            android:textColor="#000000"
            android:textSize="18sp" />
    </LinearLayout>

</LinearLayout>

kotlin GroupStatusEntity 实体类

package com.example.ppg.timeline.entity

/**
 * Created by ppg on 2017/12/18.
 * 二级Item数据列表
 */
 class GroupStatusEntity( var groupName:String, var childList:List<ChildStatusEntity>)

kotlin ChildStatusEntity实体类

package com.example.ppg.timeline.entity

/**
 * Created by ppg on 2017/12/18.
 * /** 预计完成时间 **/
 * /** 是否已完成 **/
 */
 data class ChildStatusEntity( var completeTime: String, var isfinished: Boolean)

adapter

package com.example.ppg.timeline.adapter;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;

import com.example.ppg.timeline.R;
import com.example.ppg.timeline.entity.ChildStatusEntity;
import com.example.ppg.timeline.entity.GroupStatusEntity;

import java.util.List;

/**
 * Created by ppg on 2017/12/18.
 */

public class StatusExpandAdapter extends BaseExpandableListAdapter {
    private LayoutInflater inflater = null;
    private List<GroupStatusEntity> groupList;

    /**
     * 构造方法
     *
     * @param context
     * @param oneList
     */
    public StatusExpandAdapter(Context context,
                               List<GroupStatusEntity> group_list) {
        this.groupList = group_list;
        inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    /**
     * 返回一级Item总数
     */
    @Override
    public int getGroupCount() {
        // TODO Auto-generated method stub
        return groupList.size();
    }

    /**
     * 返回二级Item总数
     */
    @Override
    public int getChildrenCount(int groupPosition) {
        if (groupList.get(groupPosition).getChildList() == null) {
            return 0;
        } else {
            return groupList.get(groupPosition).getChildList().size();
        }
    }

    /**
     * 获取一级Item内容
     */
    @Override
    public Object getGroup(int groupPosition) {
        // TODO Auto-generated method stub
        return groupList.get(groupPosition);
    }

    /**
     * 获取二级Item内容
     */
    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return groupList.get(groupPosition).getChildList().get(childPosition);
    }

    @Override
    public long getGroupId(int groupPosition) {
        // TODO Auto-generated method stub
        return groupPosition;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        // TODO Auto-generated method stub
        return childPosition;
    }

    @Override
    public boolean hasStableIds() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {

        GroupViewHolder holder = new GroupViewHolder();

        if (convertView == null) {
            convertView = inflater.inflate(R.layout.group_status_item, null);
        }
        holder.groupName = (TextView) convertView
                .findViewById(R.id.one_status_name);

        holder.groupName.setText(groupList.get(groupPosition).getGroupName());

        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {
        ChildViewHolder viewHolder = null;
        ChildStatusEntity entity = (ChildStatusEntity) getChild(groupPosition,
                childPosition);
        if (convertView != null) {
            viewHolder = (ChildViewHolder) convertView.getTag();
        } else {
            viewHolder = new ChildViewHolder();
            convertView = inflater.inflate(R.layout.child_status_item, null);
            viewHolder.twoStatusTime = (TextView) convertView
                    .findViewById(R.id.two_complete_time);
        }
        viewHolder.twoStatusTime.setText(entity.getCompleteTime());

        convertView.setTag(viewHolder);
        return convertView;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        // TODO Auto-generated method stub
        return false;
    }

    private class GroupViewHolder {
        TextView groupName;
    }

    private class ChildViewHolder {
        public TextView twoStatusTime;
    }
}

主函数调用，MainAcvitity.java

package com.example.ppg.timeline;

import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ExpandableListView;

import com.example.ppg.timeline.adapter.StatusExpandAdapter;
import com.example.ppg.timeline.entity.ChildStatusEntity;
import com.example.ppg.timeline.entity.GroupStatusEntity;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private ExpandableListView expandlistView;
    private StatusExpandAdapter statusAdapter;
    private Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context = this;
        expandlistView = (ExpandableListView) findViewById(R.id.expandlist);
        initExpandListView();
    }

    /**
     * 初始化可拓展列表
     */
    private void initExpandListView() {
        statusAdapter = new StatusExpandAdapter(context, getListData());
        expandlistView.setAdapter(statusAdapter);
        expandlistView.setGroupIndicator(null); // 去掉默认带的箭头
        expandlistView.setSelection(0);// 设置默认选中项

        // 遍历所有group,将所有项设置成默认展开
        int groupCount = expandlistView.getCount();
        for (int i = 0; i < groupCount; i++) {
            expandlistView.expandGroup(i);
        }

        expandlistView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {

            @Override
            public boolean onGroupClick(ExpandableListView parent, View v,
                                        int groupPosition, long id) {
                // TODO Auto-generated method stub
                return true;
            }
        });
    }

    private List<GroupStatusEntity> getListData() {
        List<GroupStatusEntity> groupList;
        String[] strArray = new String[] { "12月18日", "12月17日", "12月16日" , "12月15日", "12月14日"};
        String[][] childTimeArray = new String[][] {
                { "画江湖之换世门生" },
                { "天下黑白可争", "世间义理难断" },{ "唯留君之明月空悬"},
                { "纵横交错兮天下之局" }, { "谁能参悟兮世事如棋" } };
        groupList = new ArrayList<GroupStatusEntity>();
        for (int i = 0; i < strArray.length; i++) {
//            GroupStatusEntity groupStatusEntity = new GroupStatusEntity(strArray[i],);
//            groupStatusEntity.setGroupName(strArray[i]);

            List<ChildStatusEntity> childList = new ArrayList<ChildStatusEntity>();

            for (int j = 0; j < childTimeArray[i].length; j++) {
                ChildStatusEntity childStatusEntity = new ChildStatusEntity(childTimeArray[i][j],true);
//                childStatusEntity.setCompleteTime(childTimeArray[i][j]);
//                childStatusEntity.setIsfinished(true);
                childList.add(childStatusEntity);
            }
            GroupStatusEntity groupStatusEntity = new GroupStatusEntity(strArray[i],childList);

//            groupStatusEntity.setChildList(childList);
            groupList.add(groupStatusEntity);
        }
        return groupList;
    }
}