Android学习笔记二十二.使用ContentProvider实现数据共享(五).监听ContentProvider的数据改变

package com.example.android_content_4;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.ContentValues;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore.Images.Media;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.SimpleAdapter;
public class MediaProviderTest extends Activity {
 private Button  catBtn,addBtn;
 private ListView show;
 ArrayList<String> names=new ArrayList<String>();
 ArrayList<String> descs=new ArrayList<String>();
 ArrayList<String> fileNames=new ArrayList<String>();
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  catBtn=(Button)findViewById(R.id.cat);
  addBtn=(Button)findViewById(R.id.add);
  show=(ListView)findViewById(R.id.list);
  catBtn.setOnClickListener(new OnClickListener(){
   @Override
   public void onClick(View v) {
    names.clear();
    descs.clear();
    fileNames.clear();
   //1.通过ContentResolver查询所有图片信息
    Cursor cursor = getContentResolver().query(Media.EXTERNAL_CONTENT_URI,null,null,null,null);
    while(cursor.moveToNext())
    {
     //a.获取图片的显示名
     String name = cursor.getString(cursor.getColumnIndex(Media.DISPLAY_NAME));
     //b.获取图片的详细描述
     String desc = cursor.getString(cursor.getColumnIndex(Media.DESCRIPTION));
     //c.获取图片的保存位置的数据
     byte[] data = cursor.getBlob(cursor.getColumnIndex(Media.DATA));
     //d.将图片名、图片描述、图片保存路径分别添加到names、descs、fileNames集合中
     names.add(name);
     descs.add(desc);
     fileNames.add(new String(data,0,data.length-1));
    }
   
   //2.创建一个List集合，List集合的元素是Map,并将names、descs两个集合对象的数据转换到Map集合中
    List<Map<String,Object>> listItems = new ArrayList<Map<String,Object>>();
    for(int i = 0; i<names.size() ;i++)
    {
     Map<String,Object> listItem = new HashMap<String,Object>();
     listItem.put("name", names.get(i));	//获取列表中指定位置的元素，元素i的名称
     listItem.put("desc", descs.get(i)); //元素i的属性
     listItems.add(listItem);
    }
   //3.创建一个SimpleAdapter,并为show ListView组件设置Adapter
    SimpleAdapter simpleAdapter = new SimpleAdapter(
      MediaProviderTest.this,listItems
      ,R.layout.line
      ,new String[] {"name","desc"}
      ,new int[] {R.id.name,R.id.desc});
    show.setAdapter(simpleAdapter);
   }
  });
 
     //4.为show ListView的列表项单击事件添加监听器
  show.setOnItemClickListener(new OnItemClickListener(){
   @Override
   public void onItemClick(AdapterView<?> parent, View view,
     int position, long id) {
    //a.加载View.xml界面布局代表的视图
    View viewDialog=getLayoutInflater().inflate(R.layout.view, null);
    //b.获取viewDialog中Id为image的组件
    ImageView image=(ImageView)viewDialog.findViewById(R.id.image);
    //c.设置image显示指定图片
    image.setImageBitmap(BitmapFactory.decodeFile(fileNames.get(position)));
    //d.使用对话框显示用户单击的图片
    new AlertDialog.Builder(MediaProviderTest.this)
          .setView(viewDialog).setPositiveButton("确定", null)
          .show();
   }
  });
 
  //5.为add按钮的单击事件绑定监听器
  addBtn.setOnClickListener(new OnClickListener(){
   @Override
   public void onClick(View v) {
    //a.创建ContentValues对象，准备插入数据
    ContentValues values = new ContentValues();
    values.put(Media.DISPLAY_NAME, "photo");
    values.put(Media.DESCRIPTION, "示例图片");
    values.put(Media.MIME_TYPE, "image/jpeg");
    //b.插入数据，返回所插入数据对应的Uri
    Uri uri = getContentResolver().insert(Media.EXTERNAL_CONTENT_URI, values);
    //c.加载应用程序下photo图片
    Bitmap bitmap=BitmapFactory.decodeResource(MediaProviderTest.this.getResources(),R.drawable.photo);
    OutputStream os = null;
    try{
     os=getContentResolver().openOutputStream(uri);
     bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
     os.close();
    }catch(IOException e)
    {
     e.printStackTrace();
    }
   }
   
  });
 }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical" >
       
     <Button
         android:id="@+id/cat"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="查看所有图片"/>
     
     <Button
         android:id="@+id/add"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="添加图片"/>
     <ListView  
        android:id="@+id/list"  
        android:layout_width="match_parent"  
        android:layout_height="wrap_content"></ListView>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="vertical" > 
<TextView 
android:id="@+id/name" 
android:layout_width="match_parent" 
android:layout_height="wrap_content"/> 
<TextView 
android:id="@+id/desc" 
android:layout_width="match_parent" 
android:layout_height="wrap_content"/> 
</LinearLayout>
(4)点击列表项，弹出对话框布局/res/layout/view.xml
<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="vertical" > 
<ImageView 
android:id="@+id/image" 
android:layout_width="wrap_content" 
android:layout_height="wrap_content"/> 
</LinearLayout>

package com.example.android_content_5;
import android.app.Activity;
import android.database.ContentObserver;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.widget.TextView;
public class MonitorSms extends Activity {
 private TextView sms;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  sms=(TextView)findViewById(R.id.message);
 //1.为content://sms的数据改变注册监听器
  getContentResolver().registerContentObserver(Uri.parse("content://sms"),true, new SmsObserver(new Handler()));
 }
 
 //2.提供自定义的ContentObserver监听器类
 private final class SmsObserver extends ContentObserver
 {
  //a.构造方法
  public SmsObserver(Handler handler)
  {
   super(handler);
  }
  public void onChange(boolean selfChange)
  {
  //b.查询发送箱中的短信(处于正在发送状态的信息放在发送箱),即查询content://sms/outbox的全部数据
   Cursor cursor = getContentResolver().query(Uri.parse("content://sms/outbox"), null, null, null, null);
   while(cursor.moveToNext())
   {
    StringBuilder sb = new StringBuilder();
    //获取短信的发送地址
    sb.append("address=").append(cursor.getString(cursor.getColumnIndex("address")));
    //获取短信的标题
    sb.append(";subject=").append(cursor.getString(cursor.getColumnIndex("subject")));
    //获取短信的内容
    sb.append(";body=").append(cursor.getString(cursor.getColumnIndex("body")));
    //获取短信的发送时间
    sb.append(";time=").append(cursor.getLong(cursor.getColumnIndex("date")));
    System.out.println("Has Sent SMS::"+sb.toString());
   }
  }
 }
}