22、高级工具--常用号码查询，ExpandableListView的使用

实现效果图：



这些常用电话号码是存储在数据库中的，这里直接使用assets/commonnum.db

创建CommonNumberActivity以及布局文件，代码：

package com.example.mobilesafe;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;

import com.example.mobilesafe.db.CommonNumberDao;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
* Created by sing on 14-1-10.
* desc:
*/
public class CommonNumberActivity extends Activity {

public static final String TAG = "CommonNumberActivity";
private ExpandableListView elv_common_number;

public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.commonnumberactivity_layout);

elv_common_number = (ExpandableListView) findViewById(R.id.elv_common_number);

//设置适配器
elv_common_number.setAdapter(new CommonNumberAdapter());

//点击分组中的孩子view时的处理事件
elv_common_number.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
@Override
public boolean onChildClick(ExpandableListView expandableListView, View view, int i, int i2, long l) {

//取号码
String number = ((TextView) view).getText().toString().split("\n")[1];

//拨号
Intent intent = new Intent();
intent.setAction(Intent.ACTION_DIAL);
intent.setData(Uri.parse("tel:" + number));
startActivity(intent);

return false;
}
});
}

private class CommonNumberAdapter extends BaseExpandableListAdapter {

private List<String> groupNames;

private Map<Integer,List<String>> childrenCache;

public CommonNumberAdapter() {
childrenCache = new HashMap<Integer, List<String>>();
}

@Override
public View getChildView(int i, int i2, boolean b, View view, ViewGroup viewGroup) {
TextView tv;

if (view==null) {
tv = new TextView(getApplicationContext());
}else {
tv = (TextView) view;
}

tv.setTextSize(20);

String name = null;
if (childrenCache.containsKey(i)) {
name = childrenCache.get(i).get(i2);
}else {
List<String> results = CommonNumberDao.getChildrenNamesByPosition(i);
childrenCache.put(i, results);
name = results.get(i2);
}
tv.setText(name);

return tv;
}

/**
* 返回true表示分组条目可以响应单击事件
* @param i
* @param i2
* @return
*/
@Override
public boolean isChildSelectable(int i, int i2) {
return true;
}

/**
* 返回组数
* @return
*/
@Override
public int getGroupCount() {
return CommonNumberDao.getGroupCount();
}

/**
* 一组有多少条目
* @param i
* @return
*/
@Override
public int getChildrenCount(int i) {
return CommonNumberDao.getChildrenCount(i);
}

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

@Override
public Object getChild(int i, int i2) {
return null;
}

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

@Override
public Object getGroup(int i) {
return null;
}

@Override
public long getChildId(int i, int i2) {
return i2;
}

@Override
public View getGroupView(int i, boolean b, View view, ViewGroup viewGroup) {
TextView tv;

if (view==null) {
tv = new TextView(getApplicationContext());
}else {
tv = (TextView) view;
}
tv.setTextSize(28);
if (groupNames == null) {
groupNames = CommonNumberDao.getGroupNames();
}
tv.setText("        " + groupNames.get(i));

return tv;
}
}

}

布局文件：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView style="@style/title_center_text"
android:text="常用号码" />
<View style="@style/dot_splitter_view"/>
<ExpandableListView
android:id="@+id/elv_common_number"
android:layout_height="match_parent"
android:layout_width="match_parent"/>
</LinearLayout>

代码中使用的获取分组名、个数、分组条目个数、条目名称等功能封装在CommonNumberDao类中，其实就是对数据库的一个操作使用，代码：

package com.example.mobilesafe.db;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

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

/**
* Created by sing on 14-1-15.
* desc:
*/
public class CommonNumberDao {
private static final String TAG = "CommonNumberDao";
public static final String FILE_DIR = "/data/data/com.example.mobilesafe/files/";

/**
* 获取常用号码分组数
* @return
*/
public static int getGroupCount() {
int count = 0;

String path = FILE_DIR + "commonnum.db";
SQLiteDatabase db = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READONLY);
if (db.isOpen()) {
Cursor cursor = db.rawQuery("select * from classlist", null);
count = cursor.getCount();
cursor.close();
db.close();
}

return count;
}

/**
* 获取常用号码分组名
* @return
*/
public static List<String> getGroupNames() {
List<String> groupNames = new ArrayList<String>();
String path = FILE_DIR + "commonnum.db";
SQLiteDatabase db = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READONLY);
if (db.isOpen()) {
Cursor cursor = db.rawQuery("select name from classlist", null);
while (cursor.moveToNext()) {
groupNames.add(cursor.getString(0));
}
cursor.close();
db.close();
}

return groupNames;
}

/**
* 获取指定分组的名称
* @param groupPosition
* @return
*/
public static String getGroupNameByPosition(int groupPosition) {
String name = null;

String path = FILE_DIR + "commonnum.db";
SQLiteDatabase db = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READONLY);
if (db.isOpen()) {
Cursor cursor = db.rawQuery("select name from classlist where idx=?", new String[]{(groupPosition + 1) + ""});
cursor.moveToFirst();
name = cursor.getString(0);
cursor.close();
db.close();
}

return name;
}

/**
* 获取指定分组的条目个数
* @param groupPosition
* @return
*/
public static int getChildrenCount(int groupPosition) {
int count = 0;

String path = FILE_DIR + "commonnum.db";
SQLiteDatabase db = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READONLY);
if (db.isOpen()) {
Cursor cursor = db.rawQuery("select * from table" + (groupPosition + 1), null);
count = cursor.getCount();
cursor.close();
db.close();
}

return count;
}

/**
* 获取指定分组指定条目的名称和电话号码
* @param groupPosition
* @param childrenPosition
* @return
*/
public static String getChildNameByPosition(int groupPosition, int childrenPosition) {
String result = null;
String path = FILE_DIR + "commonnum.db";
SQLiteDatabase db = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READONLY);
if (db.isOpen()) {
Cursor cursor = db.rawQuery("select name,number from table" + (groupPosition + 1) + " where _id=?", new String[]{(childrenPosition + 1) + ""});
if (cursor.moveToFirst()) {
result = cursor.getString(0) + "\n" + cursor.getString(1);
}

cursor.close();
db.close();
}

return result;
}

/**
* 获取某分组下所有的项目名称和电话号码
* @param groupPosition
* @return
*/
public static List<String> getChildrenNamesByPosition(int groupPosition) {
List<String> results = new ArrayList<String>();
String path = FILE_DIR + "commonnum.db";
SQLiteDatabase db = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READONLY);
if (db.isOpen()) {
Cursor cursor = db.rawQuery("select name,number from table" + (groupPosition + 1), null);
while (cursor.moveToNext()) {
results.add(cursor.getString(0) + "\n" + cursor.getString(1));
}
cursor.close();
db.close();
}

return results;
}
}