使用ContentObserver实现短信提醒功能

通过查询语句：Cursor cursor = mContext.getContentResolver().query(Uri.parse("content://sms"), null, "type = 1 and read = 0", null, null);打印可以看到数据库中所有的列字段

String names[] = cursor.getColumnNames();
name = _id i = 0 //短消息序号自动递增 如100
name = thread_id i = 1 //序号，同一发信人的id相同
name = address i = 2 //发件人地址，手机号.如：10086
name = person i = 3 //发件人，返回一个数字就是联系人列表里的序号，陌生人为null
name = date i = 4 //日期，long型
name = date_sent i = 5
name = protocol i = 6 //协议 0 SMS_RPOTO, 1 MMS_PROTO
name = read i = 7 //是否阅读 0未读， 1已读
name = status i = 8 //状态 -1接收，0 complete, 64 pending, 128 failed
name = type i = 9
//ALL = 0;
//INBOX = 1; 接收
//SENT = 2; 发送
//DRAFT = 3;
//OUTBOX = 4;
//FAILED = 5;
//QUEUED = 6;
name = reply_path_present i = 10
name = subject i = 11 //短信的主题，一般为null
name = body i = 12 //短信内容
name = service_center i = 13 //短信服务中心号码编号，如+8613800752011
name = locked i = 14
name = error_code i = 15
name = seen i = 16
name = timed i = 17
name = deleted i = 18
name = sync_state i = 19
name = marker i = 20
name = source i = 21
name = bind_id i = 22
name = mx_status i = 23
name = mx_id i = 24
name = out_time i = 25
name = account i = 26
name = block_type i = 27
name = sim_id i = 28
name = advanced_seen i = 29以上作了注释的是较为常用的，我们可以只查询出常用的列，查询函数原型：query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)

第二个参数：projection，可以写上我们需要的列，第三个：selection是查询的条件。
private static final String[] PROJECTION = new String[] { SMS._ID,// 0
SMS.TYPE,// 1
SMS.ADDRESS,// 2
SMS.SUBJECT,// 3
SMS.BODY,// 4
SMS.DATE,// 5
SMS.THREAD_ID,// 6
SMS.READ,// 7
SMS.PROTOCOL // 8
};
Cursor cursor = mContext.getContentResolver().query(
SMS.CONTENT_URI, PROJECTION, "type = 1 and read = 0", null,
null);关于每个字符的类型可以看下packages/providers/TelephonyProvider/src/com/android/providers/telephony/MmsSmsDatabaseHelper.java文件是如何创建表的：

db.execSQL("CREATE TABLE pdu_temp (" +
Mms._ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
Mms.THREAD_ID + " INTEGER," +
Mms.DATE + " INTEGER," +
Mms.DATE_SENT + " INTEGER DEFAULT 0," +
Mms.MESSAGE_BOX + " INTEGER," +
Mms.READ + " INTEGER DEFAULT 0," +
Mms.MESSAGE_ID + " TEXT," +
Mms.SUBJECT + " TEXT," +
Mms.SUBJECT_CHARSET + " INTEGER," +
Mms.CONTENT_TYPE + " TEXT," +
Mms.CONTENT_LOCATION + " TEXT," +
Mms.EXPIRY + " INTEGER," +
Mms.MESSAGE_CLASS + " TEXT," +
Mms.MESSAGE_TYPE + " INTEGER," +
Mms.MMS_VERSION + " INTEGER," +
Mms.MESSAGE_SIZE + " INTEGER," +
Mms.PRIORITY + " INTEGER," +
Mms.READ_REPORT + " INTEGER," +
Mms.REPORT_ALLOWED + " INTEGER," +
Mms.RESPONSE_STATUS + " INTEGER," +
Mms.STATUS + " INTEGER," +
Mms.TRANSACTION_ID + " TEXT," +
Mms.RETRIEVE_STATUS + " INTEGER," +
Mms.RETRIEVE_TEXT + " TEXT," +
Mms.RETRIEVE_TEXT_CHARSET + " INTEGER," +
Mms.READ_STATUS + " INTEGER," +
Mms.CONTENT_CLASS + " INTEGER," +
Mms.RESPONSE_TEXT + " TEXT," +
Mms.DELIVERY_TIME + " INTEGER," +
Mms.DELIVERY_REPORT + " INTEGER," +
Mms.LOCKED + " INTEGER DEFAULT 0," +
Mms.SEEN + " INTEGER DEFAULT 0," +
Mms.TEXT_ONLY + " INTEGER DEFAULT 0" +
");");

只查询出我们关心的字段就可以了。

下面就来看下短信提醒功能如何实现的。
程序结构



先定义一个常量类SMS.java

package com.deng.datawidget.sms;

import android.net.Uri;
import android.provider.BaseColumns;

public class SMS implements BaseColumns {
public static final Uri CONTENT_URI = Uri.parse("content://sms");
public static final String FILTER = "!imichat";
public static final String TYPE = "type";
public static final String THREAD_ID = "thread_id";
public static final String ADDRESS = "address";
public static final String PERSON_ID = "person";
public static final String DATE = "date";
public static final String READ = "read";
public static final String SUBJECT = "subject";
public static final String BODY = "body";
public static final String PROTOCOL = "protocol";
public static final int MESSAGE_TYPE_ALL = 0;
public static final int MESSAGE_TYPE_INBOX = 1;
public static final int MESSAGE_TYPE_SENT = 2;
public static final int MESSAGE_TYPE_DRAFT = 3;
public static final int MESSAGE_TYPE_OUTBOX = 4;
public static final int MESSAGE_TYPE_FAILED = 5; // for failed outgoing
// messages
public static final int MESSAGE_TYPE_QUEUED = 6; // for messages to send
// later
public static final int PROTOCOL_SMS = 0;// SMS_PROTO
public static final int PROTOCOL_MMS = 1;// MMS_PROTO
}定义SmsObserver继承ContentObserver监听数据库的变化

package com.deng.datawidget.sms;

import java.sql.Date;
import java.text.SimpleDateFormat;
import java.util.Locale;

import android.content.Context;
import android.database.ContentObserver;
import android.database.Cursor;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

/**
* 短信监听器，根据数据库的变化去查询未读短信，可以做到短信提醒功能
*
*
*/
public class SmsObserver extends ContentObserver {
private static final String TAG = "SmsObserver";
private Context mContext;
private Handler mHandler;
private static final String[] PROJECTION = new String[] { SMS._ID,// 0
SMS.TYPE,// 1
SMS.ADDRESS,// 2
SMS.SUBJECT,// 3
SMS.BODY,// 4
SMS.DATE,// 5
SMS.THREAD_ID,// 6
SMS.READ,// 7
SMS.PROTOCOL // 8
};

public SmsObserver(Context context, Handler handler) {
super(handler);
mHandler = handler;
mContext = context;
}

@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
// 每当有新短信到来时，使用我们获取短消息的方法
int newMsgNum = getNewSmsCount();
Message msg = mHandler.obtainMessage();
msg.what = 2;
msg.obj = newMsgNum;
mHandler.sendMessage(msg);
Log.i(TAG, "onChange newMsgNum = " + newMsgNum);
}

private int getNewSmsCount() {
int result = 0;
try {
Cursor cursor = mContext.getContentResolver().query(
SMS.CONTENT_URI, PROJECTION, "type = 1 and read = 0", null,
null);
if (cursor != null) {
MessageItem msg;
result = cursor.getCount();
while (cursor.moveToNext()) {
int id = cursor.getInt(cursor.getColumnIndex(SMS._ID));
int type = cursor.getInt(cursor.getColumnIndex(SMS.TYPE));
int protocol = cursor.getInt(cursor
.getColumnIndex(SMS.PROTOCOL));
String address = cursor.getString(cursor
.getColumnIndex(SMS.ADDRESS));
String body = cursor.getString(cursor
.getColumnIndex(SMS.BODY));
String subject = cursor.getString(cursor
.getColumnIndex(SMS.SUBJECT));
SimpleDateFormat dateFormat = new SimpleDateFormat(
"yyyy-MM-dd hh:mm:ss", Locale.getDefault());
Date d = new Date(cursor.getLong(cursor
.getColumnIndex(SMS.DATE)));
String date = dateFormat.format(d);

msg = new MessageItem();
msg.setId(id);
msg.setType(type);
msg.setProtocol(protocol);
msg.setDate(date);
msg.setAddress(address);
msg.setSubject(subject);
msg.setBody(body);
Log.i(TAG, msg.toString());
}
String names[] = cursor.getColumnNames();
int i = 0;
for (String name : names) {
Log.i(TAG, "name = " + name + " i = " + i);
i++;
}
cursor.close();
}
} catch (Exception e) {
Log.e(TAG, e.toString());
}
return result;
}
}

在activity中注册内容观察者

package com.deng.datawidget;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.Toast;

import com.deng.datawidget.sms.SMS;
import com.deng.datawidget.sms.SmsObserver;

public class MainActivity extends Activity {

private static final String TAG = "MainActivity";
private SmsObserver content = null;

private Handler mHandler = new Handler() {

@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
final int what = msg.what;
switch (what) {
case 2:
int num = (int) msg.obj;
Toast.makeText(MainActivity.this, "你有：" + num + " 条未读短信",
Toast.LENGTH_LONG).show();
break;

default:
break;
}
super.handleMessage(msg);
}

};

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

content = new SmsObserver(this, mHandler);
// 注册短信变化监听
getContentResolver().registerContentObserver(SMS.CONTENT_URI, true,
content);
}

@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
getContentResolver().unregisterContentObserver(content);
}
}

相应代码下载：http://download.csdn.net/detail/deng0zhaotai/9250353

以上方式只是ContentObserver的一种使用方法，可以用来监听你需要监听的数据库是否有变化，如有变化作出相应的回应。