android 学习随笔二十一（内容提供者 ）

一、内容提供者
* 应用的数据库是不允许其他应用访问的
* 内容提供者的作用就是让别的应用访问到你的私有数据
* 自定义内容提供者，继承ContentProvider类，重写增删改查方法，在方法中写增删改查数据库的代码，举例增方法

@Override
public Uri insert(Uri uri, ContentValues values) {
db.insert("person", null, values);
return uri;
}
* 在清单文件中定义内容提供者的标签，注意必须要有authorities属性，这是内容提供者的主机名，功能类似地址

<provider android:name="com.itheima.contentprovider.PersonProvider"
android:authorities="com.itheima.person"
android:exported="true"
></provider>

 

通过UriMatcher um = new UriMatcher(UriMatcher.NO_MATCH)指定表

um.addURI("com.itheima.people", "person/#", 3);//content://com.itheima.people/person/10，#匹配任何数字，通常作为WHERE条件使用

 

vnd.android.cursor.dir/   多条数据

vnd.android.cursor.item/  单条数据

 

 

package com.itheima.mycontentprovider.db;import java.io.Serializable;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;import android.os.Parcelable;public class MyOpenHelper extends SQLiteOpenHelper {    public MyOpenHelper(Context context) {        super(context, "people.db", null, 2);    }    @Override    public void onCreate(SQLiteDatabase db) {        db.execSQL("create table person(_id integer primary key autoincrement, name char(10), phone char(20), money integer(10))");            }    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {        db.execSQL("create table handsome(_id integer primary key autoincrement, name char(10), phone char(20))");    }}

定义数据库

package com.itheima.mycontentprovider;import com.itheima.mycontentprovider.db.MyOpenHelper;import android.content.ContentProvider;import android.content.ContentUris;import android.content.ContentValues;import android.content.UriMatcher;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.net.Uri;public class PersonProvider extends ContentProvider {    private SQLiteDatabase db;    //创建uri匹配器    UriMatcher um = new UriMatcher(UriMatcher.NO_MATCH);    {        //添加匹配规则        //arg0:主机名        //arg1:路径        //arg2:匹配码        um.addURI("com.itheima.people", "person", 1);//content://com.itheima.people/person        um.addURI("com.itheima.people", "handsome", 2);//content://com.itheima.people/handsome        um.addURI("com.itheima.people", "person/#", 3);//content://com.itheima.people/person/10    }        //内容提供者创建时调用    @Override    public boolean onCreate() {        MyOpenHelper oh = new MyOpenHelper(getContext());        db = oh.getWritableDatabase();        return false;    }    //values:其他应用要插的数据    @Override    public Uri insert(Uri uri, ContentValues values) {        if(um.match(uri) == 1){            db.insert("person", null, values);                        //数据库改变了,内容提供者发出通知            //arg0:通知发到哪个uri上，注册在这个uri上的内容观察者都可以收到通知            getContext().getContentResolver().notifyChange(uri, null);        }        else if(um.match(uri) == 2){            db.insert("handsome", null, values);                        getContext().getContentResolver().notifyChange(uri, null);        }        else{            throw new IllegalArgumentException("uri传错啦傻逼");        }        return uri;    }    @Override    public int delete(Uri uri, String selection, String[] selectionArgs) {        int i = 0;        if(um.match(uri) == 1){            i = db.delete("person", selection, selectionArgs);        }        else if(um.match(uri) == 2){            i = db.delete("handsome", selection, selectionArgs);        }        else{            throw new IllegalArgumentException("uri又传错啦傻逼");        }                return i;    }        @Override    public int update(Uri uri, ContentValues values, String selection,            String[] selectionArgs) {        int i = db.update("person", values, selection, selectionArgs);        return i;    }        @Override    public Cursor query(Uri uri, String[] projection, String selection,            String[] selectionArgs, String sortOrder) {        Cursor cursor = null;        if(um.match(uri) == 1){            cursor = db.query("person", projection, selection, selectionArgs, null, null, sortOrder, null);        }        else if(um.match(uri) == 2){            cursor = db.query("handsome", projection, selection, selectionArgs, null, null, sortOrder, null);        }        else if(um.match(uri) == 3){            //取出uri末尾携带的数字            long id = ContentUris.parseId(uri);            cursor = db.query("person", projection, "_id = ?", new String[]{"" + id}, null, null, sortOrder, null);        }        return cursor;    }        //返回通过指定uri获取的数据的mimetype    @Override    public String getType(Uri uri) {        if(um.match(uri) == 1){            return "vnd.android.cursor.dir/person";        }        else if(um.match(uri) == 2){            return "vnd.android.cursor.dir/handsome";        }        else if(um.match(uri) == 3){            return "vnd.android.cursor.item/person";        }        return null;    }    }

内容提供者

package com.itheima.mycontentprovider;import android.os.Bundle;import android.app.Activity;import android.view.Menu;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);            }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.main, menu);        return true;    }    }

MainActivity

package com.itheima.mycontentprovider;import com.itheima.mycontentprovider.db.MyOpenHelper;import android.test.AndroidTestCase;public class Test extends AndroidTestCase {    public void test(){        MyOpenHelper oh = new MyOpenHelper(getContext());        oh.getWritableDatabase();    }}

test

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.itheima.mycontentprovider"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" /><instrumentation android:name="android.test.InstrumentationTestRunner"    android:targetPackage="com.itheima.mycontentprovider"></instrumentation>    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >                <uses-library android:name="android.test.runner"/>        <activity            android:name="com.itheima.mycontentprovider.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>                <provider             android:name="com.itheima.mycontentprovider.PersonProvider"                    android:authorities="com.itheima.people"                        android:exported="true">        </provider>    </application></manifest>

AndroidManifest

 

* 创建一个其他应用，访问自定义的内容提供者，实现对数据库的插入操作

public void click(View v){
//得到内容分解器对象
ContentResolver cr = getContentResolver();
ContentValues cv = new ContentValues();
cv.put("name", "小方");
cv.put("phone", 138856);
cv.put("money", 3000);
//url:内容提供者的主机名
cr.insert(Uri.parse("content://com.itheima.person"), cv);
}

package com.itheima.other;import android.net.Uri;import android.os.Bundle;import android.app.Activity;import android.content.ContentResolver;import android.content.ContentValues;import android.database.Cursor;import android.view.Menu;import android.view.View;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    public void insert(View v){        //通过内容提供者把数据插入01数据库        //1.获取contentResolver        ContentResolver resolver = getContentResolver();        //2.访问内容提供者，插入数据        ContentValues values = new ContentValues();        values.put("name", "流氓润");        values.put("phone", 138992);        values.put("money", 14000);        //arg0:指定内容提供者的主机名        resolver.insert(Uri.parse("content://com.itheima.people/person"), values);                values.clear();        values.put("name", "侃哥");        values.put("phone", 15999);        //arg0:指定内容提供者的主机名        resolver.insert(Uri.parse("content://com.itheima.people/handsome"), values);    }        public void delete(View v){        ContentResolver resolver = getContentResolver();        int i = resolver.delete(Uri.parse("content://com.itheima.people"), "name = ?", new String[]{"凤姐"});        System.out.println(i);    }        public void update(View v){        ContentResolver resolver = getContentResolver();        ContentValues values = new ContentValues();        values.put("money", 16001);        int i = resolver.update(Uri.parse("content://com.itheima.people"), values, "name = ?", new String[]{"春晓"});        System.out.println(i);    }        public void query(View v){        ContentResolver resolver = getContentResolver();        Cursor cursor = resolver.query(Uri.parse("content://com.itheima.people/person"), null, null, null, null);        while(cursor.moveToNext()){            String name = cursor.getString(1);            String phone = cursor.getString(2);            String money = cursor.getString(3);            System.out.println(name + ";" + phone + ";" + money);        }    }    public void queryOne(View v){        ContentResolver resolver = getContentResolver();        Cursor cursor = resolver.query(Uri.parse("content://com.itheima.people/person/4"), null, null, null, null);        if(cursor.moveToNext()){            String name = cursor.getString(1);            String phone = cursor.getString(2);            String money = cursor.getString(3);            System.out.println(name + ";" + phone + ";" + money);        }    }}

View Code

 

UriMatcher
* 用于判断一条uri跟指定的多条uri中的哪条匹配
* 添加匹配规则

//指定多条uri
um.addURI("com.itheima.person", "person", PERSON_CODE);
um.addURI("com.itheima.person", "company", COMPANY_CODE);
//#号可以代表任意数字
um.addURI("com.itheima.person", "person/#", QUERY_ONE_PERSON_CODE);
* 通过Uri匹配器可以实现操作不同的表

@Override
public Uri insert(Uri uri, ContentValues values) {
if(um.match(uri) == PERSON_CODE){
db.insert("person", null, values);
}
else if(um.match(uri) == COMPANY_CODE){
db.insert("company", null, values);
}
else{
throw new IllegalArgumentException();
}
return uri;
}
* 如果路径中带有数字，把数字提取出来的api

int id = (int) ContentUris.parseId(uri);

二、获取系统短信

短信数据库
* 只需要关注sms表
* 只需要关注4个字段
* body：短信内容
* address:短信的发件人或收件人号码（跟你聊天那哥们的号码）
* date：短信时间
* type：1为收到，2为发送
###读取系统短信，首先查询源码获得短信数据库内容提供者的主机名和路径，然后访问内容提供者（掌握）

ContentResolver cr = getContentResolver();
Cursor c = cr.query(Uri.parse("content://sms"), new String[]{"body", "date", "address", "type"}, null, null, null);
while(c.moveToNext()){
String body = c.getString(0);
String date = c.getString(1);
String address = c.getString(2);
String type = c.getString(3);
System.out.println(body+";" + date + ";" + address + ";" + type);
}

package com.itheima.getsms;import android.net.Uri;import android.os.Bundle;import android.app.Activity;import android.content.ContentResolver;import android.database.Cursor;import android.view.Menu;import android.view.View;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    public void click1(View v){        ContentResolver resolver = getContentResolver();        Cursor cursor = resolver.query(Uri.parse("content://sms"), new String[]{"address", "date", "type", "body"}, null, null, null);        while(cursor.moveToNext()){            String address = cursor.getString(0);            long date = cursor.getLong(1);            int type = cursor.getInt(2);            String body = cursor.getString(3);                        System.out.println(address + ";" + date + ";" + type + ";" + body);        }    }    }

MainActivity

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.itheima.getsms"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <uses-permission android:name="android.permission.READ_SMS"/>    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.itheima.getsms.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

AndroidManifest

 三、插入系统短信

插入系统短信

ContentResolver cr = getContentResolver();
ContentValues cv = new ContentValues();
cv.put("body", "您尾号为XXXX的招行储蓄卡收到转账1,000,000人民币");
cv.put("address", 95555);
cv.put("type", 1);
cv.put("date", System.currentTimeMillis());
cr.insert(Uri.parse("content://sms"), cv);
* 插入查询系统短信需要注册权限

package com.itheima.insertsms;import android.net.Uri;import android.os.Bundle;import android.app.Activity;import android.content.ContentResolver;import android.content.ContentValues;import android.view.Menu;import android.view.View;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    public void click(View v){        Thread t = new Thread(){            @Override            public void run() {                try {                    sleep(7000);                } catch (InterruptedException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }                ContentResolver resolver = getContentResolver();                ContentValues values = new ContentValues();                values.put("address", 95555);                values.put("date", System.currentTimeMillis());                values.put("type", 1);                values.put("body", "您尾号为XXXX的招行储蓄卡收到转账1,000,000");                resolver.insert(Uri.parse("content://sms"), values);            }        };        t.start();            }    }

MainActivity

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.itheima.insertsms"    android:versionCode="1"    android:versionName="1.0" >        <uses-permission android:name="android.permission.WRITE_SMS"/>    <uses-permission android:name="android.permission.READ_SMS"/>    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.itheima.insertsms.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

AndroidManifest

 四、联系人数据库

* raw\_contacts表：
* contact_id：联系人id
* data表：联系人的具体信息，一个信息占一行
* data1：信息的具体内容
* raw\_contact_id：联系人id，描述信息属于哪个联系人
* mimetype_id：描述信息是属于什么类型
* mimetypes表：通过mimetype_id到该表查看具体类型

五、读取联系人
* 先查询raw\_contacts表拿到联系人id

Cursor cursor = cr.query(Uri.parse("content://com.android.contacts/raw_contacts"), new String[]{"contact_id"}, null, null, null);
* 然后拿着联系人id去data表查询属于该联系人的信息

Cursor c = cr.query(Uri.parse("content://com.android.contacts/data"), new String[]{"data1", "mimetype"}, "raw_contact_id = ?", new String[]{contactId}, null);
* 得到data1字段的值，就是联系人的信息，通过mimetype判断是什么类型的信息

while(c.moveToNext()){
String data1 = c.getString(0);
String mimetype = c.getString(1);
if("vnd.android.cursor.item/email_v2".equals(mimetype)){
contact.setEmail(data1);
}
else if("vnd.android.cursor.item/name".equals(mimetype)){
contact.setName(data1);
}
else if("vnd.android.cursor.item/phone_v2".equals(mimetype)){
contact.setPhone(data1);
}
}

package com.itheima.getcontacts.domain;public class Contact {    private String name;    private String phone;    private String email;    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getPhone() {        return phone;    }    public void setPhone(String phone) {        this.phone = phone;    }    public String getEmail() {        return email;    }    public void setEmail(String email) {        this.email = email;    }    @Override    public String toString() {        return "Contact [name=" + name + ", phone=" + phone + ", email="                + email + "]";    }        }

Contact

package com.itheima.getcontacts;import com.itheima.getcontacts.domain.Contact;import android.net.Uri;import android.os.Bundle;import android.app.Activity;import android.content.ContentResolver;import android.database.Cursor;import android.view.Menu;import android.view.View;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    public void click(View v){        ContentResolver resolver = getContentResolver();                Cursor cursor = resolver.query(Uri.parse("content://com.android.contacts/raw_contacts"), new String[]{"contact_id"},                 null, null, null);        while(cursor.moveToNext()){            String contactId = cursor.getString(0);            //使用联系人id作为where条件去查询data表，查询出属于该联系人的信息            Cursor cursorData = resolver.query(Uri.parse("content://com.android.contacts/data"), new String[]{"data1", "mimetype"}, "raw_contact_id = ?",                     new String[]{contactId}, null);//            Cursor cursorData = resolver.query(Uri.parse("content://com.android.contacts/data"), null, "raw_contact_id = ?", //                    new String[]{contactId}, null);            //            int count = cursorData.getColumnCount();//            for (int i = 0; i < count; i++) {//                System.out.println(cursorData.getColumnName(i));//            }                        Contact contact = new Contact();            while(cursorData.moveToNext()){                String data1 = cursorData.getString(0);                String mimetype = cursorData.getString(1);//                System.out.println(data1 + ";" + mimetype);                if("vnd.android.cursor.item/email_v2".equals(mimetype)){                    contact.setEmail(data1);                }                else if("vnd.android.cursor.item/phone_v2".equals(mimetype)){                    contact.setPhone(data1);                }                else if("vnd.android.cursor.item/name".equals(mimetype)){                    contact.setName(data1);                }            }            System.out.println(contact.toString());        }    }    }

MainActivity

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.itheima.getcontacts"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <uses-permission android:name="android.permission.READ_CONTACTS"/>    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.itheima.getcontacts.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

View Code

 

六、插入联系人
* 先查询raw\_contacts表，确定新的联系人的id应该是多少
* 把确定的联系人id插入raw\_contacts表

cv.put("contact_id", _id);
cr.insert(Uri.parse("content://com.android.contacts/raw_contacts"), cv);
* 在data表插入数据
* 插3个字段：data1、mimetype、raw\_contact_id

cv = new ContentValues();
cv.put("data1", "赵六");
cv.put("mimetype", "vnd.android.cursor.item/name");
cv.put("raw_contact_id", _id);
cr.insert(Uri.parse("content://com.android.contacts/data"), cv);

cv = new ContentValues();
cv.put("data1", "1596874");
cv.put("mimetype", "vnd.android.cursor.item/phone_v2");
cv.put("raw_contact_id", _id);
cr.insert(Uri.parse("content://com.android.contacts/data"), cv);

package com.itheima.insertcontact;import android.net.Uri;import android.os.Bundle;import android.app.Activity;import android.content.ContentResolver;import android.content.ContentValues;import android.database.Cursor;import android.view.Menu;import android.view.View;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    public void click(View v){        ContentResolver resolver = getContentResolver();        //先查询最新的联系人的主键，主键+1，就是要插入的联系人id        Cursor cursor = resolver.query(Uri.parse("content://com.android.contacts/raw_contacts"), new String[]{"_id"}, null, null, null);        int _id = 0;        if(cursor.moveToLast()){            _id = cursor.getInt(0);        }        _id++;                //插入联系人id        ContentValues values = new ContentValues();        values.put("contact_id", _id);        resolver.insert(Uri.parse("content://com.android.contacts/raw_contacts"), values);                //把具体联系人信息插入data表        values.clear();        values.put("data1", "剪刀手坤哥");        values.put("mimetype", "vnd.android.cursor.item/name");        values.put("raw_contact_id", _id);        resolver.insert(Uri.parse("content://com.android.contacts/data"), values);                values.clear();        values.put("data1", "8899667");        values.put("mimetype", "vnd.android.cursor.item/phone_v2");        values.put("raw_contact_id", _id);        resolver.insert(Uri.parse("content://com.android.contacts/data"), values);    }    }

MainActivity

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.itheima.insertcontact"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <uses-permission android:name="android.permission.READ_CONTACTS"/>    <uses-permission android:name="android.permission.WRITE_CONTACTS"/>    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.itheima.insertcontact.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

AndroidManifest

七、内容观察者

* 当数据库数据改变时，内容提供者会发出通知，在内容提供者的uri上注册一个内容观察者，就可以收到数据改变的通知

cr.registerContentObserver(Uri.parse("content://sms"), true, new MyObserver(new Handler()));

class MyObserver extends ContentObserver{

public MyObserver(Handler handler) {
super(handler);
// TODO Auto-generated constructor stub
}

//内容观察者收到数据库发生改变的通知时，会调用此方法
@Override
public void onChange(boolean selfChange) {

}

}

package com.itheima.contentobserver;import android.net.Uri;import android.os.Bundle;import android.os.Handler;import android.app.Activity;import android.content.ContentResolver;import android.database.ContentObserver;import android.view.Menu;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                //注册内容观察者，观察者就生效了，可以接受内容提供者发出的通知        ContentResolver resolver = getContentResolver();        //arg0:指定接收哪个内容提供者发出的通知        resolver.registerContentObserver(Uri.parse("content://sms"),                 true, //如果为true,以这个uri作为开头的uri上的数据改变了,该内容观察者都会收到通知                new MyObserver(new Handler()));    }        class MyObserver extends ContentObserver{        public MyObserver(Handler handler) {            super(handler);            // TODO Auto-generated constructor stub        }                @Override        public void onChange(boolean selfChange) {            // TODO Auto-generated method stub            super.onChange(selfChange);            System.out.println("短信数据库改变");        }    }}

View Code

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.itheima.contentobserver"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.itheima.contentobserver.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

View Code

 

  在内容提供者中发通知的代码

ContentResolver cr = getContext().getContentResolver();
//发出通知，所有注册在这个uri上的内容观察者都可以收到通知
cr.notifyChange(uri, null);

 接收一内容提供者发送的通知

package com.itheima.receivenotify;import android.net.Uri;import android.os.Bundle;import android.os.Handler;import android.app.Activity;import android.database.ContentObserver;import android.view.Menu;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                //注册内容观察者接收01发送的通知        getContentResolver().registerContentObserver(Uri.parse("content://com.itheima.people"),                 true, new ContentObserver(new Handler()) {                    @Override                    public void onChange(boolean selfChange) {                        // TODO Auto-generated method stub                        super.onChange(selfChange);                        System.out.println("01数据库改变");                    }                });    }    }

View Code

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.itheima.receivenotify"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.itheima.receivenotify.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

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