ContentProvider学习

1.创建类继承ContentProvider类，并实现增、删、改、查功能。

 public static final String AUTHORITY = "com.diysoul.listshowdemo.providers.PersonContentProvider";

     public static final int INSERT_CODE = 0;

     public static final int DELETE_CODE = 1;

     public static final int UPDATE_CODE = 2;

     public static final int QUARY_CODE = 3;

     public static final int QUARY_BY_ID_CODE = 4;

     public static final String INSERT = "insert";

     public static final String UPDATE = "update";

     public static final String DELETE = "delete";

     public static final String QUERY = "query";

     /*
      * 根据_id查询 #为通配符，表示一个数字 *为通配符，表示任意一个字符串
      */
     public static final String QUERY_BY_ID = "query/#";

     private PersonSqliteHelper mySqlHelper;

     static UriMatcher uriMatcher;

     static {
         uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
         uriMatcher.addURI(AUTHORITY, INSERT, INSERT_CODE);
         uriMatcher.addURI(AUTHORITY, UPDATE, UPDATE_CODE);
         uriMatcher.addURI(AUTHORITY, DELETE, DELETE_CODE);
         uriMatcher.addURI(AUTHORITY, QUERY, QUARY_CODE);
         uriMatcher.addURI(AUTHORITY, QUERY_BY_ID, QUARY_BY_ID_CODE);
     }

     @Override
     public boolean onCreate() {
         mySqlHelper = new PersonSqliteHelper(this.getContext());
         return false;
     }

     @Override
     public Cursor query(Uri uri, String[] projection, String selection,
             String[] selectionArgs, String sortOrder) {
         switch (uriMatcher.match(uri)) {
         case QUARY_CODE: {
             SQLiteDatabase db = mySqlHelper.getReadableDatabase();
             if (db.isOpen()) {
                 Cursor cursor = db.query("persons", projection, selection,
                         selectionArgs, null, null, sortOrder);
                 return cursor;
             }
         }
             break;
         case QUARY_BY_ID_CODE: {
             SQLiteDatabase db = mySqlHelper.getReadableDatabase();
             if (db.isOpen()) {
                 long id = ContentUris.parseId(uri);
                 Cursor cursor = db.query("persons", projection, "_id = ?",
                         new String[] { String.valueOf(id) }, null, null,
                         sortOrder);
                 return cursor;
             }
         }
             break;
         default:
             throw new IllegalArgumentException("cannot match uri:" + uri);
         }
         return null;
     }

     @Override
     public String getType(Uri uri) {
         switch(uriMatcher.match(uri)) {
         case QUARY_BY_ID_CODE:
             return "vnd.android.cursor.item/persons";
         case QUARY_CODE:
             return "vnd.android.cursor.dir/persons";
         default:
             break;
         }
         return null;
     }

     @Override
     public Uri insert(Uri uri, ContentValues values) {
         switch (uriMatcher.match(uri)) {
         case INSERT_CODE:
             SQLiteDatabase db = mySqlHelper.getReadableDatabase();
             if (db.isOpen()) {
                 long id = db.insert(PersonSqliteHelper.PERSON_TABLE, null,
                         values);
                 db.close();
                 return ContentUris.withAppendedId(uri, id);
             }
             break;
         default:
             throw new IllegalArgumentException("cannot match uri:" + uri);
         }
         return null;
     }

     @Override
     public int delete(Uri uri, String selection, String[] selectionArgs) {
         switch (uriMatcher.match(uri)) {
         case DELETE_CODE:
             SQLiteDatabase db = mySqlHelper.getReadableDatabase();
             if (db.isOpen()) {
                 int count = db.delete(PersonSqliteHelper.PERSON_TABLE,
                         selection, selectionArgs);
                 db.close();
                 return count;
             }
             break;
         default:
             throw new IllegalArgumentException("cannot match uri:" + uri);
         }
         return 0;
     }

     @Override
     public int update(Uri uri, ContentValues values, String selection,
             String[] selectionArgs) {
         switch (uriMatcher.match(uri)) {
         case UPDATE_CODE:
             SQLiteDatabase db = mySqlHelper.getReadableDatabase();
             if (db.isOpen()) {
                 int count = db.update(PersonSqliteHelper.PERSON_TABLE, values,
                         selection, selectionArgs);
                 db.close();
                 return count;
             }
             break;
         default:
             throw new IllegalArgumentException("cannot match uri:" + uri);
         }
         return 0;
     }

2.在AndroidManifest.xml中进行配置，在application根节点下增加

        <provider
            android:name="com.diysoul.listshowdemo.providers.PersonContentProvider"
            android:authorities="com.diysoul.listshowdemo.providers.PersonContentProvider"
            android:exported="true" >
        </provider>

3.创建应用程序访问功能

 public void runQuery() {
         Log.v(TAG, "[runQuery]in");
         Uri uri = Uri.parse("content://com.diysoul.listshowdemo.providers.PersonContentProvider/query");
         ContentResolver resolver = this.getContext().getContentResolver();
         Log.v(TAG, "[runQuery]call query");
         Cursor cursor = resolver.query(uri, new String[]{"_id", "name", "tel"}, null, null, null);
         Log.v(TAG, "[runQuery]cursor=" + cursor);
         if(cursor != null && cursor.getCount() > 0) {
             while(cursor.moveToNext()) {
                 int id = cursor.getInt(0);
                 String name = cursor.getString(1);
                 String tel = cursor.getString(2);
                 Log.v(TAG, "id=" + id + ",name=" + name + ",tel=" + tel);
             }
         }
     }

4.监听数据改变

 　　　　　ContentObserver smsObserver = new ContentObserver(msmHandler) {

             @Override
             public void onChange(boolean selfChange) {
                 Log.v(TAG, "[onChange]in selfChange=" + selfChange);
             }

             @Override
             public void onChange(boolean selfChange, Uri uri) {
                 Log.v(TAG, "[onChange]in selfChange=" + selfChange + ", uri=" + uri);
                 //重新从查询等操作，以改变保存的数据
                 readSms();
                 //通知事件适配器数据改变，此时会自动刷新适配器关联 的ListView
                 smsListAdapter.notifyDataSetChanged();
             }
         };
         getContentResolver().registerContentObserver(Uri.parse(SMS_CONTENT), true, smsObserver);