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  • ContentProvider ContentResolver ContentObserver 内容:提供、访问、监听

    内容提供

    public class PersonContentProvider extends ContentProvider{

    private static final String AUTHORITY = "com.itheima28.sqlitedemo.providers.PersonContentProvider";
     private static final int PRESON_INSERT_CODE = 0; // 操作person表添加的操作的uri匹配码

    UriMatcher uriMatcher;

    private PersonSQLiteOpenHelper mOpenHelper; 

    static{

    uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);

    uriMatcher.addURI(AUTHORITY, "person/insert", PRESON_INSERT_CODE);

    }

    @Override
     public boolean onCreate() {
      mOpenHelper = new PersonSQLiteOpenHelper(getContext());
      return true;
     }

    @Override
     public Uri insert(Uri uri, ContentValues values) {
      
      switch (uriMatcher.match(uri)) {
      case PRESON_INSERT_CODE: // 添加人到person表中
       SQLiteDatabase db = mOpenHelper.getWritableDatabase();
       
       if(db.isOpen()) {
        
        long id = db.insert("person", null, values);
        
        db.close();
        
        return ContentUris.withAppendedId(uri, id);
       }
       break;
      default:
       throw new IllegalArgumentException("uri不匹配: " + uri);
      }
      return null;
     }

    }

    UriMatcher

    内容访问

    ContentResolver resolver = getContext().getContentResolver();

    uri = resolver.insert(uri, values);

    int count = resolver.delete(uri, where, selectionArgs);

    int count = resolver.update(uri, values, "_id = ?", new String[]{"20"});

    Cursor cursor = resolver.query(uri, new String[]{"_id", "name", "age"}, null, null, "_id desc");

    内容监听

    resolver.registerContentObserver(Uri.parse("content://sms/"), true, new MyContentObserver(new Handler()));   //注册内容监听

    class MyContentObserver extends ContentObserver {

      private static final String TAG = "MyContentObserver";

      public MyContentObserver(Handler handler) {

       super(handler);  

     }

      /**    * 当被监听的内容发生改变时回调    */   

    @Override   

    public void onChange(boolean selfChange) {

       Log.i(TAG, "短信改变了");  

      Uri uri = Uri.parse("content://sms/outbox"); // 发件箱的uri        // 查询发件箱的内容  

      Cursor cursor = getContentResolver().query(uri, new String[]{"address", "date", "body"}, null, null, null);    

    if(cursor != null && cursor.getCount() > 0) {          String address;     long date;     String body;   

      while(cursor.moveToNext()) {      address = cursor.getString(0);      date = cursor.getLong(1);      body = cursor.getString(2);      

         Log.i(TAG, "号码: " + address + ", 日期: " + date + ", 内容: " + body);     }

        cursor.close();   

     }   }  }

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  • 原文地址:https://www.cnblogs.com/hanxing/p/4558229.html
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