第49章、可伸縮列表ExpandableListView（從零開始學Android）

如果希望展示的列表可以收縮和展開，就像QQ好友列表一樣，我們可以使用ExpandableListView。

 

一、設計界面

　　1、布局文件

　　打開activity_main.xml文件。

　　輸入以下代碼：

[html] view plain copy  

1. <?xml version="1.0" encoding="utf-8"?>  
2.  <LinearLayout   
3.      xmlns:android="http://schemas.android.com/apk/res/android"  
4.      android:layout_width="match_parent"  
5.      android:layout_height="match_parent"  
6.      android:orientation="vertical" >  
7.      <ExpandableListView   
8.          android:id="@+id/province"  
9.          android:layout_width="match_parent"  
10.          android:layout_height="match_parent"  
11.          android:background="#EFEFEF">  
12.      </ExpandableListView>   
13.  </LinearLayout>  

 

二、程序文件

　　打開“src/com.genwoxue.expandable/MainActivity.java”文件。

　　然後輸入以下代碼：

[java] view plain copy  

1. package com.genwoxue.expandablelistview;  
2.   
3. import android.app.Activity;  
4. import android.graphics.Color;  
5. import android.os.Bundle;  
6. import android.view.Gravity;  
7. import android.view.View;  
8. import android.view.ViewGroup;  
9. import android.widget.AbsListView;  
10. import android.widget.BaseExpandableListAdapter;  
11. import android.widget.ExpandableListAdapter;  
12. import android.widget.ExpandableListView;  
13. import android.widget.ExpandableListView.OnChildClickListener;  
14. import android.widget.LinearLayout;  
15. import android.widget.TextView;  
16. import android.widget.Toast;  
17.   
18. public class MainActivity extends Activity {  
19.   
20.         protected void onCreate(Bundle savedInstanceState) {  
21.             super.onCreate(savedInstanceState);  
22.             setContentView(R.layout.activity_main);  
23.   
24.             final ExpandableListAdapter adapter = new BaseExpandableListAdapter() {  
25.                 //設置組視圖的顯示文字  
26.                 private String[] province = new String[] { "河南省", "河北省", "山東省","山西省" };  
27.                 //子視圖顯示文字  
28.                 private String[][] city = new String[][] {  
29.                         { "鄭州市", "開封市", "新鄉市", "安陽市", "南陽市"},  
30.                         { "石家莊市", "邯鄲市", "保定市", "廊坊市"},  
31.                         { "濟南市", "青島市", "日照市", "煙台市", "威海市" },  
32.                         { "太原市", "大同市", "晉城市", "呂梁市", "長治市" }  
33.                 };  
34.                   
35.                 //自己定義一個獲得文字信息的方法  
36.                 TextView getTextView() {  
37.                     AbsListView.LayoutParams lp = new AbsListView.LayoutParams(  
38.                             ViewGroup.LayoutParams.MATCH_PARENT, 64);  
39.                     TextView textView = new TextView(MainActivity.this);  
40.                     textView.setLayoutParams(lp);  
41.                     textView.setGravity(Gravity.CENTER_VERTICAL);  
42.                     textView.setPadding(36, 0, 0, 0);  
43.                     textView.setTextSize(20);  
44.                     textView.setTextColor(Color.BLACK);  
45.                     return textView;  
46.                 }  
47.   
48.                   
49.                 //重寫ExpandableListAdapter中的各個方法  
50.                 @Override  
51.                 public int getGroupCount() {  
52.                     return province.length;  
53.                 }  
54.   
55.                 @Override  
56.                 public Object getGroup(int groupPosition) {  
57.                     return province[groupPosition];  
58.                 }  
59.   
60.                 @Override  
61.                 public long getGroupId(int groupPosition) {  
62.                     return groupPosition;  
63.                 }  
64.   
65.                 @Override  
66.                 public int getChildrenCount(int groupPosition) {  
67.                     return city[groupPosition].length;  
68.                 }  
69.   
70.                 @Override  
71.                 public Object getChild(int groupPosition, int childPosition) {  
72.                     return city[groupPosition][childPosition];  
73.                 }  
74.   
75.                 @Override  
76.                 public long getChildId(int groupPosition, int childPosition) {  
77.                     return childPosition;  
78.                 }  
79.   
80.                 @Override  
81.                 public boolean hasStableIds() {  
82.                     return true;  
83.                 }  
84.   
85.                 @Override  
86.                 public View getGroupView(int groupPosition, boolean isExpanded,  
87.                         View convertView, ViewGroup parent) {  
88.                     LinearLayout ll = new LinearLayout(MainActivity.this);  
89.                     ll.setOrientation(0);  
90.                     TextView textView = getTextView();  
91.                     textView.setTextColor(Color.BLACK);  
92.                     textView.setText(getGroup(groupPosition).toString());  
93.                     ll.addView(textView);  
94.   
95.                     return ll;  
96.                 }  
97.   
98.                 @Override  
99.                 public View getChildView(int groupPosition, int childPosition,  
100.                         boolean isLastChild, View convertView, ViewGroup parent) {  
101.                     LinearLayout ll = new LinearLayout(MainActivity.this);  
102.                     ll.setOrientation(0);  
103.                     TextView textView = getTextView();  
104.                     textView.setText(getChild(groupPosition, childPosition).toString());  
105.                     ll.addView(textView);  
106.                     return ll;  
107.                 }  
108.   
109.                 @Override  
110.                 public boolean isChildSelectable(int groupPosition,int childPosition) {  
111.                     return true;  
112.                 }  
113.   
114.             };  
115.               
116.             ExpandableListView expandableListView = (ExpandableListView) findViewById(R.id.province);  
117.             expandableListView.setAdapter(adapter);  
118.               
119.             //設置item點擊的監聽器  
120.             expandableListView.setOnChildClickListener(new OnChildClickListener() {  
121.   
122.                 @Override  
123.                 public boolean onChildClick(ExpandableListView parent, View v,  
124.                         int groupPosition, int childPosition, long id) {  
125.   
126.                     Toast.makeText(  
127.                             MainActivity.this,  
128.                             adapter.getChild(groupPosition, childPosition).toString(),  
129.                             Toast.LENGTH_SHORT).show();  
130.   
131.                     return false;  
132.                 }  
133.             });  
134.         }  
135.     }  

三、運行結果