Android ExpandableListView的使用

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一、MainActivity要继承ExpandableListActivity。效果是当单击ListView的子项是显示另一个ListView。

package com.example.explear;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import android.app.Activity;
import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.transition.SidePropagation;
import android.widget.SimpleExpandableListAdapter;public class MainActivity extends ExpandableListActivity {
private static final String NAME = "NAME";
private static final String IS_EVEN = "IS_EVEN";
private SimpleExpandableListAdapter eListAdapter; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState); List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();
List<List<Map<String, String>>> childDataList = new ArrayList<List<Map<String, String>>>();
for (int i = 0; i < 10; i++) {
Map<String, String> curGroupMap = new HashMap<String, String>();
groupData.add(curGroupMap);
curGroupMap.put(NAME, "Group" + i);
curGroupMap.put(IS_EVEN, (i % 2 == 0) ? "This group is even"
: "this group is odd");
List<Map<String, String>> children = new ArrayList<Map<String, String>>();
for (int j = 0; j < 8; j++) {
Map<String, String> curChildMap = new HashMap<String, String>();
children.add(curChildMap);
curChildMap.put(NAME, "Child" + i);
curChildMap.put(IS_EVEN, (i % 2 == 0) ? "This chile is even"
: "this chile is odd");
}
childDataList.add(children);
}
eListAdapter = new SimpleExpandableListAdapter(this, groupData,
android.R.layout.simple_expandable_list_item_2, new String[] {
NAME, IS_EVEN }, new int[] { android.R.id.text1,
android.R.id.text2 }, childDataList,
android.R.layout.simple_expandable_list_item_2, new String[] {
NAME, IS_EVEN }, new int[] { android.R.id.text1,
android.R.id.text2 });
setListAdapter(eListAdapter);
}
}

1、groupData是父数据，childDataList是子数据。

2、android.R.layout.simple_expandable_list_item_2表示list的实现方式

3、new String[] { NAME,IS_EVEN} list需要显示的数据的键值，真正显示的是键对应的值

效果图：

二、数据源：SimpleCursorTreeAdapter的使用

package com.example.explear;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import android.app.Activity;
import android.app.ExpandableListActivity;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.Contacts.People;
import android.transition.SidePropagation;
import android.widget.ExpandableListAdapter;
import android.widget.SimpleCursorTreeAdapter;
import android.widget.SimpleExpandableListAdapter;public class MainActivity extends ExpandableListActivity {
private int mGroupIdColumnIndex;
private String mPhoneNumberProjection[] = new String[] { People.Phones._ID,
People.Phones.NUMBER }; private ExpandableListAdapter mAdapter; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState); // 搜索
Cursor groupCursor = managedQuery(People.CONTENT_URI, new String[] {
People._ID, People.NAME }, null, null, null);
// 创建ID 列索引
mGroupIdColumnIndex = groupCursor.getColumnIndexOrThrow(People._ID); // 创建adapter
mAdapter = new MyExpandableListAdapter(groupCursor, this,
android.R.layout.simple_expandable_list_item_1,
android.R.layout.simple_expandable_list_item_1,
new String[] { People.NAME }, new int[] { android.R.id.text1 },
new String[] { People.NUMBER },
new int[] { android.R.id.text1 });
setListAdapter(mAdapter);
}; public class MyExpandableListAdapter extends SimpleCursorTreeAdapter {
public MyExpandableListAdapter(Cursor cursor, Context context,
int groupLayout, int childLayout, String[] groupFrom,
int[] groupTo, String[] childrenFrom, int[] childrenTo) {
super(context, cursor, groupLayout, groupFrom, groupTo,
childLayout, childrenFrom, childrenTo);
} @Override
protected Cursor getChildrenCursor(Cursor groupCursor) {
// 传进来一个组，返回一个对组内所有子组的cursor
// 返回一个指向这个联系人电话的箭头
Uri.Builder builder = People.CONTENT_URI.buildUpon();
ContentUris.appendId(builder,
groupCursor.getLong(mGroupIdColumnIndex));
builder.appendEncodedPath(People.Phones.CONTENT_DIRECTORY);
Uri phoneNumberUri = builder.build(); return managedQuery(phoneNumberUri, mPhoneNumberProjection, null,
null, null); }
}
}

效果图

三、通过BaseExpandableListAdapter绑定数据

activity_main.xml

注意这里的ExpandableListView的id设置需要使用@android:id/list，否则会报

Your content must have a ExpandableListView whose id attribute is 'android.R.id.list'错误

package com.example.explear;import android.R.anim;
import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;public class MainActivity extends ExpandableListActivity {
private String[] groups = { "group1", "group2", "group3", "group4" };
private String[][] children = {
{ "g1 item1", "g1 item2", "g1 item3", "g1 item4" },
{ "g2 item1", "g2 item2", "g2 item3", "g2 item4" },
{ "g3 item1", "g3 item2" }, { "g4 item1", "g4 item2" } }; private ExpandableListView expandableListView;
private TextView tView = null; @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tView = (TextView) findViewById(R.id.textView1);
expandableListView = (ExpandableListView) findViewById(android.R.id.list); BaseExpandableListAdapter adapter = new BaseExpandableListAdapter() { @Override
public boolean isChildSelectable(int groupPosition,
int childPosition) {
String string = groups[groupPosition]
+ children[groupPosition][childPosition];
tView.setText(string);
return true;
} @Override
public boolean hasStableIds() {
return false;
} @Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
LinearLayout layout = new LinearLayout(MainActivity.this);
layout.setOrientation(0);
layout.setPadding(50, 0, 0, 0);
ImageView imageView = new ImageView(MainActivity.this);
imageView.setImageResource(R.drawable.ic_launcher);
layout.addView(imageView); TextView textView = getTextView();
textView.setText(getGroup(groupPosition).toString());
layout.addView(textView);
return layout;
} @Override
public long getGroupId(int groupPosition) {
return groupPosition;
} @Override
public int getGroupCount() {
return groups.length;
} @Override
public Object getGroup(int groupPosition) {
return groups[groupPosition];
} @Override
public int getChildrenCount(int groupPosition) {
return children[groupPosition].length;
} @Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
TextView textView = getTextView();
textView.setText(getChild(groupPosition, childPosition)
.toString()); return textView;
} @Override
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
} @Override
public Object getChild(int groupPosition, int childPosition) {
return children[groupPosition][childPosition];
}
};
expandableListView.setAdapter(adapter);
} protected TextView getTextView() {
AbsListView.LayoutParams lParams = new AbsListView.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT, 64);
TextView textView = new TextView(MainActivity.this);
textView.setLayoutParams(lParams);
textView.setPadding(20, 0, 0, 0);
textView.setGravity(Gravity.LEFT | Gravity.CENTER_VERTICAL);
return textView;
}
}