Android中常常要用到ListView,但也经常要用到ExpandableListView,ListView是显示列表,而ExpandableListView显示的是分类的列表;
下面用一个例子来说明:
还可以点击触发事件;
代码如下:
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.xiaozhang.listactivitytest.MainActivity" > <ExpandableListView android:id="@id/android:list" android:layout_width="match_parent" android:layout_height="match_parent" android:drawSelectorOnTop="false" /> </RelativeLayout>
第一层列表group.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/RelativeLayout01" android:layout_width="match_parent" android:layout_height="wrap_content" android:paddingBottom="4dp" android:paddingLeft="12dp" android:paddingRight="12dp" > <TextView android:id="@+id/groupTo" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="10dp" android:paddingLeft="30dp" android:paddingTop="10dp" android:shadowColor="#40000000" android:shadowDx="0" android:shadowDy="8" android:shadowRadius="1" android:textSize="16sp" android:textStyle="bold" /> </RelativeLayout>
第二层列表child.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/RelativeLayout01" android:layout_width="match_parent" android:layout_height="wrap_content" android:paddingBottom="4dp" android:paddingLeft="12dp" android:paddingRight="12dp" > <ImageView android:id="@+id/image" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:background="@drawable/icon" android:paddingTop="12dp" /> <TextView android:id="@+id/childTo" android:layout_width="wrap_content" android:layout_height="wrap_content" android:paddingBottom="10dp" android:paddingLeft="60dp" android:paddingTop="10dp" android:textSize="16sp" /> </RelativeLayout>
MainActivity.java
package com.xiaozhang.listactivitytest; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.ExpandableListActivity; import android.os.Bundle; import android.view.View; import android.widget.ExpandableListView; import android.widget.SimpleExpandableListAdapter; import android.widget.Toast; public class MainActivity extends ExpandableListActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); List<Map<String, String>> groups = new ArrayList<Map<String, String>>(); // 第一层列表数据 Map<String, String> group1 = new HashMap<String, String>(); Map<String, String> group2 = new HashMap<String, String>(); Map<String, String> group3 = new HashMap<String, String>(); Map<String, String> group4 = new HashMap<String, String>(); group1.put("group", "湘北高中"); group2.put("group", "岭南高中"); group3.put("group", "翔阳高中"); group4.put("group", "海南高中"); groups.add(group1); groups.add(group2); groups.add(group3); groups.add(group4); // 第二层列表数据 List<List<Map<String, String>>> childs = new ArrayList<List<Map<String, String>>>(); // 第二层列表的第一个子列表数据 List<Map<String, String>> child1 = new ArrayList<Map<String, String>>(); Map<String, String> child1Data1 = new HashMap<String, String>(); child1Data1.put("child", "樱木花道"); Map<String, String> child1Data2 = new HashMap<String, String>(); child1Data2.put("child", "流川枫"); Map<String, String> child1Data3 = new HashMap<String, String>(); child1Data3.put("child", "宫城良田"); Map<String, String> child1Data4 = new HashMap<String, String>(); child1Data4.put("child", "三井寿"); child1.add(child1Data1); child1.add(child1Data2); child1.add(child1Data3); child1.add(child1Data4); // 第二层列表的第二个子列表数据 List<Map<String, String>> child2 = new ArrayList<Map<String, String>>(); Map<String, String> child2Data1 = new HashMap<String, String>(); child2Data1.put("child", "仙道彰"); Map<String, String> child2Data2 = new HashMap<String, String>(); child2Data2.put("child", "鱼住纯"); Map<String, String> child2Data3 = new HashMap<String, String>(); child2Data3.put("child", "福田吉兆"); child2.add(child2Data1); child2.add(child2Data2); child2.add(child2Data3); // 第二层列表的第三个子列表数据 List<Map<String, String>> child3 = new ArrayList<Map<String, String>>(); Map<String, String> child3Data1 = new HashMap<String, String>(); child3Data1.put("child", "藤真健司"); Map<String, String> child3Data2 = new HashMap<String, String>(); child3Data2.put("child", "花形透"); Map<String, String> child3Data3 = new HashMap<String, String>(); child3Data3.put("child", "长谷川一志"); child3.add(child3Data1); child3.add(child3Data2); child3.add(child3Data3); // 第二层列表的第四个子列表数据 List<Map<String, String>> child4 = new ArrayList<Map<String, String>>(); Map<String, String> child4Data1 = new HashMap<String, String>(); child4Data1.put("child", "牧绅一"); Map<String, String> child4Data2 = new HashMap<String, String>(); child4Data2.put("child", "神宗一郎"); Map<String, String> child4Data3 = new HashMap<String, String>(); child4Data3.put("child", "清田信长"); Map<String, String> child4Data4 = new HashMap<String, String>(); child4Data4.put("child", "高砂一马"); child4.add(child4Data1); child4.add(child4Data2); child4.add(child4Data3); child4.add(child4Data4); // 把子列表数据放入第二层列表中 childs.add(child1); childs.add(child2); childs.add(child3); childs.add(child4); SimpleExpandableListAdapter listAdapter = new SimpleExpandableListAdapter( this, groups, R.layout.group, new String[] { "group" }, new int[] { R.id.groupTo }, childs, R.layout.child, new String[] { "child" }, new int[] { R.id.childTo }); setListAdapter(listAdapter); } @Override public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) { Toast.makeText( this, parent.getItemAtPosition(groupPosition) + " " + parent.getItemAtPosition(childPosition + groupPosition + 1), Toast.LENGTH_LONG).show(); return super.onChildClick(parent, v, groupPosition, childPosition, id); } }
注意:
(1)@id/android:list,是系统自带的ID,如果要使用ListActivity或我们使用的ExpandableListActivity,就必须要使用@id/android:list;
而ListActivity会根据id自动查找ListView的引用;如在 Activity 中使用 setListAdapter(adapter) 时就默认设置到了这个list上。如果按一般控件的写法 <ListView android:id="@+id/myListView" …… />,则需要 findViewById 先得到控件对像,再调用对像的 setListAdapter(adapter);