基础学习总结（六）--getContentRolver()的应用、内容监听者ContentObserver

ContentResolver / getContentResolver()
 
外界的程序通过ContentResolver接口可以访问ContentProvider提供的数据，在Activity当中通过getContentResolver()可以得到当前应用的 ContentResolver实例。ContentResolver提供的接口和ContentProvider中需要实现的接口对应，具体可以查看API Doc，不过可以发现ContentResolver里面的方法很多都是final或者static的。在实际应用中，我们很少实现ContentResolver抽象类，更多时候通过getContentResolver()从一个Activity或其它应用程序组件的实现里获取一个ContentResolver：

短信的uri地址:"content:\\sms\"

 1 public class MainActivity extends Activity {
 2 
 3     @Override
 4     protected void onCreate(Bundle savedInstanceState) {
 5         super.onCreate(savedInstanceState);
 6         setContentView(R.layout.activity_main);
 7         
 8     }
 9     
10     /*
11      * 备份短信点击事件*/
12     public void backupSms(View v){
13         //1.查出所有短信
14         Uri uri = Uri.parse("content://sms/");
15         //通过上下对象的getContentRolver方法获得ContentResolver实例
16         ContentResolver resolver = getContentResolver();
17         //获得游标Cursor对象
18         Cursor cor= resolver.query(uri, new String[]{"_id","address","date","type","body"}, null, null, null);
19         if(cor!=null&&cor.getCount()>0){
20             List<SmsInfo> list=new ArrayList<SmsInfo>();
21             SmsInfo sms;
22             while(cor.moveToNext()){
23                 sms=new SmsInfo();
24                 sms.setsId(cor.getInt(0));
25                 sms.setAddress(cor.getString(1));
26                 sms.setDate(cor.getLong(2));
27                 sms.setType(cor.getInt(3));
28                 sms.setBody(cor.getString(4));
29                 list.add(sms);
30             }
31             cor.close();
32             Log.w("MainActivity", "list中条数："+String.valueOf(list.size()));
33             //2.存到本地
34             writeToLocal(list);
35         }
36         
37         
38     }
39     
40     private void writeToLocal(List<SmsInfo> smslist){
41         
42         try {
43             XmlSerializer srlz= Xml.newSerializer();//得到序列化对象
44             /*动态获取sd卡地址
45              * String state=Environment.getExternalStorageState();
46             if(Environment.MEDIA_MOUNTED.equals(state)){
47                 return;
48             }
49             File sdcardFile=Environment.getExternalStorageDirectory();
50             File f=new File(sdcardFile,"sms.xml");*/
51             FileOutputStream fos=new FileOutputStream("/mnt/sdcard/sms.xml");
52             //将数据写入xml文本
53             srlz.setOutput(fos, "utf-8");
54             
55             srlz.startDocument("utf-8", true);
56             
57             srlz.startTag(null, "SmsInfo");
58             for (SmsInfo s : smslist) {
59                 srlz.startTag(null, "sms");
60                 srlz.attribute(null, "id", String.valueOf(s.getsId()));
61                 
62                 srlz.startTag(null, "address");
63                 srlz.text(s.getAddress());
64                 srlz.endTag(null, "address");
65                 
66                 srlz.startTag(null, "date");
67                 srlz.text(String.valueOf(s.getDate()));
68                 srlz.endTag(null, "date");
69                 
70                 srlz.startTag(null, "type");
71                 srlz.text(String.valueOf(s.getType()));
72                 srlz.endTag(null, "type");
73                 
74                 srlz.startTag(null, "body");
75                 srlz.text(s.getBody());
76                 srlz.endTag(null, "body");
77                 
78                 
79                 srlz.endTag(null, "sms");
80             }
81             
82             srlz.endTag(null, "SmsInfo");
83             
84             srlz.endDocument();
85             
86             Toast.makeText(this, "保存成功", 0).show();
87             
88         } catch (Exception e) {
89             Toast.makeText(this, "保存失败", 0).show();
90             e.printStackTrace();
91             
92         } 
93     }
94 }
备份短信实例

添加外部读写权限与本地读取权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

<uses-permission android:name="android.permission.READ_SMS"/>

联系人的uri地址：

content://com.android.contacts/raw_contacts
content://com.android.contacts/data

 

  1 public class MainActivity extends Activity {
  2 
  3     private static final String TAG = "MainActivity";
  4 
  5     @Override
  6     protected void onCreate(Bundle savedInstanceState) {
  7         super.onCreate(savedInstanceState);
  8         setContentView(R.layout.activity_main);
  9     }
 10 
 11     private void printCursor(Cursor cursor) {
 12         if(cursor != null && cursor.getCount() > 0) {
 13             
 14             while(cursor.moveToNext()) {
 15                 
 16                 int columnCount = cursor.getColumnCount(); // 列的总数
 17                 
 18                 for (int i = 0; i < columnCount; i++) {
 19                     String columnName = cursor.getColumnName(i);    // 取对应i位置的列的名称
 20                     String columnValue = cursor.getString(i); // 取出对应i位置的列的值
 21                     
 22                     Log.i(TAG, "当前是第" + cursor.getPosition() + "行: " + columnName + " = " + columnValue);
 23                 }
 24             }
 25             cursor.close();
 26         }
 27     }
 28 
 29     /**
 30      * 查询联系人
 31      * @param v
 32      */
 33     public void queryContacts(View v) {
 34         // 1. 去raw_contacts表中取所有联系人的_id
 35         Uri uri = Uri.parse("content://com.android.contacts/raw_contacts");
 36         Uri dataUri = Uri.parse("content://com.android.contacts/data");
 37         
 38         Cursor cursor = getContentResolver().query(uri, new String[]{"_id"}, null, null, null);
 39 //        printCursor(cursor);
 40         if(cursor != null && cursor.getCount() > 0) {
 41             
 42             while(cursor.moveToNext()) {
 43                 int id = cursor.getInt(0);
 44                 // 2. 去data表中根据上面取到的_id查询对应id的数据.
 45                 
 46                 //where语句
 47                 String selection = "raw_contact_id = ?";
 48                 //where语句需要的值
 49                 String[] selectionArgs = {String.valueOf(id)};
 50                     //                                                需要的字段
 51                 Cursor c = getContentResolver().query(dataUri, new String[]{"data1", "mimetype"}, 
 52                         selection, selectionArgs, null);
 53                 if(c != null && c.getCount() > 0) {
 54                     
 55                     while(c.moveToNext()) {
 56                         String mimetype = c.getString(1);        // 当前取的是mimetype的值
 57                         String data1 = c.getString(0);        // 当前取的是data1数据
 58                         
 59                         if("vnd.android.cursor.item/phone_v2".equals(mimetype)) {
 60                             Log.i(TAG, "号码: " + data1);
 61                         } else if("vnd.android.cursor.item/name".equals(mimetype)) {
 62                             Log.i(TAG, "姓名: " + data1);
 63                         } else if("vnd.android.cursor.item/email_v2".equals(mimetype)) {
 64                             Log.i(TAG, "邮箱: " + data1);
 65                         }
 66                     }
 67                     c.close();
 68                 }
 69             }
 70             cursor.close();
 71         }
 72 
 73     }
 74     
 75     public void addContacts(View v) {
 76         Uri uri = Uri.parse("content://com.android.contacts/raw_contacts");
 77         Uri dataUri = Uri.parse("content://com.android.contacts/data");
 78         // 1. 在raw_contacts表中添加一个记录
 79         
 80         // 取raw_contacts表中contact_id的值
 81         Cursor cursor = getContentResolver().query(uri, new String[]{"contact_id"}, null, null, "contact_id desc limit 1");
 82         if(cursor != null && cursor.moveToFirst()) {
 83             int contact_id = cursor.getInt(0);
 84             contact_id ++;
 85             cursor.close();
 86             
 87             ContentValues values = new ContentValues();
 88             values.put("contact_id", contact_id);
 89             getContentResolver().insert(uri, values);
 90 
 91             // 2. 根据上面添加记录的id, 取data表中添加三条数据
 92             
 93             // 存号码
 94             values = new ContentValues();
 95             values.put("mimetype", "vnd.android.cursor.item/phone_v2");
 96             values.put("data1", "10086");
 97             values.put("raw_contact_id", contact_id);
 98             getContentResolver().insert(dataUri, values);
 99             
100             // 存姓名
101             values = new ContentValues();
102             values.put("mimetype", "vnd.android.cursor.item/name");
103             values.put("data1", "中国移动");
104             values.put("raw_contact_id", contact_id);
105             getContentResolver().insert(dataUri, values);
106             
107             // 存姓名
108             values = new ContentValues();
109             values.put("mimetype", "vnd.android.cursor.item/email_v2");
110             values.put("data1", "10086@kengni.com");
111             values.put("raw_contact_id", contact_id);
112             getContentResolver().insert(dataUri, values);
113         }
114 
115     }
116 }
获取联系人

添加联系人的读写sd卡权限

<uses-permission android:name="android.permission.READ_CONTACTS"/>
<uses-permission android:name="android.permission.WRITE_CONTACTS"/>

 

ContentObServer应用：

1 首先创建一个ContentObserver的子类，然后实现里面的onChange方法，监听的Uri中的数据发生变化的时候，会调用onchange方法。

2 注册ContentObserver。

 1 public class MainActivity extends Activity {
 2 
 3     @Override
 4     protected void onCreate(Bundle savedInstanceState) {
 5         super.onCreate(savedInstanceState);
 6         setContentView(R.layout.activity_main);
 7         
 8         // 监听系统短信
 9         
10         ContentResolver resolver = getContentResolver();
11         
12         // 注册一个内容观察者观察短信数据库
13         resolver.registerContentObserver(Uri.parse("content://sms/"), true, new MyContentObserver(new Handler()));
14     }
15     
16     /**
17      * 内容观察者
18      */
19     class MyContentObserver extends ContentObserver {
20 
21         private static final String TAG = "MyContentObserver";
22 
23         public MyContentObserver(Handler handler) {
24             super(handler);
25         }
26 
27         /**
28          * 当被监听的内容发生改变时回调
29          */
30         @Override
31         public void onChange(boolean selfChange) {
32             Log.i(TAG, "短信改变了");
33             Uri uri = Uri.parse("content://sms/outbox");    // 发件箱的uri
34             
35             // 查询发件箱的内容
36             Cursor cursor = getContentResolver().query(uri, new String[]{"address", "date", "body"}, null, null, null);
37             if(cursor != null && cursor.getCount() > 0) {
38                 
39                 String address;
40                 long date;
41                 String body;
42                 while(cursor.moveToNext()) {
43                     address = cursor.getString(0);
44                     date = cursor.getLong(1);
45                     body = cursor.getString(2);
46                     
47                     Log.i(TAG, "号码: " + address + ", 日期: " + date + ", 内容: " + body);
48                 }
49                 cursor.close();
50             }
51         }
52     }
53 }
View Code

 

posted @ 2015-06-19 10:06  大胖儿在努力  阅读(258)  评论(0)  编辑  收藏  举报