ExpandableListView

package cgg.com.angry;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private ExpandableListView mExpandView;
    private String[] titles = {
            "我的好友", "我的同事", "我的同學", "我的朋友", "我的家人"
    };
    private String[][] children = {
            {"好友1", "好友2", "好友3", "好友4", "好友5", "好友6", "好友7", "好友8",},
            {"同事A", "同事B", "同事C", "同事D", "同事E",},
            {"同學甲", "同學乙", "同學丙", "同學丁", "同學戊", "同學己", "同學庚",},
            {"木有朋友腫麼破"},
            {"耳", "雲", "仍", "晜", "來", "玄", "曾", "孫", "子", "父", "祖", "曾", "高", "天", "烈", "太", "遠", "鼻"}
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mExpandView = findViewById(R.id.mExpandView);
        mExpandView.setAdapter(new MyExpandViewAdapter());
        // 取消默認的角標
        // mExpandView.setGroupIndicator(null);
        // 設置子條目的點擊事件
        mExpandView.setOnChildClickListener(null);
        // 設置一級條目的點擊事件
        mExpandView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
            @Override
            public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) {
                return false;
            }
        });
    }

    class MyExpandViewAdapter extends BaseExpandableListAdapter {

        @Override
        public int getGroupCount() {
            return titles.length;
        }

        @Override
        public int getChildrenCount(int groupPosition) {
            return children[groupPosition].length;
        }

        @Override
        public String getGroup(int groupPosition) {
            return titles[groupPosition];
        }

        @Override
        public String getChild(int groupPosition, int childPosition) {
            return children[groupPosition][childPosition];
        }

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

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

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

        @Override
        public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
            ViewHolder viewHolder;
            if (convertView == null) {
                convertView = View.inflate(MainActivity.this, R.layout.parent, null);
                TextView textView = convertView.findViewById(R.id.title);
                ImageView img = convertView.findViewById(R.id.jjaa);
                viewHolder = new ViewHolder(textView, img);
                convertView.setTag(viewHolder);
            } else {
                viewHolder = (ViewHolder) convertView.getTag();
            }
            viewHolder.textView.setText(titles[groupPosition]);

            // isExpanded是否展開
            if (isExpanded) {
                viewHolder.imageView.setImageResource(R.drawable.down);
            } else {
                viewHolder.imageView.setImageResource(R.drawable.right);
            }
            return convertView;
        }

        @Override
        public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
            ViewHolder viewHolder;
            if (convertView == null) {
                convertView = View.inflate(MainActivity.this, R.layout.parent, null);
                convertView.setPadding(30,0,0,0);
                TextView textView = convertView.findViewById(R.id.title);
                ImageView img = convertView.findViewById(R.id.jjaa);
                viewHolder = new ViewHolder(textView, img);
                convertView.setTag(viewHolder);
            } else {
                viewHolder = (ViewHolder) convertView.getTag();
            }
            viewHolder.textView.setText(children[groupPosition][childPosition]);
            viewHolder.imageView.setImageBitmap(null);
            return convertView;
        }

        @Override // 可以被子項 選中
        public boolean isChildSelectable(int groupPosition, int childPosition) {
            return true;
        }
    }

    class ViewHolder {
        TextView textView;
        ImageView imageView;

        public ViewHolder(TextView textView, ImageView imageView) {
            this.textView = textView;
            this.imageView = imageView;
        }
    }
}