Android移动应用基础教程【使用内容提供者共享数据】

//获取相应操作的Uri，Uri.parse()方法是将字符串转化成Uri对象。
  Uri uri = Uri.parse("content://cn.itcast.mycontentprovider/person"); 
  //获取ContentResolver对象
    ContentResolver resolver = context.getContentResolver();
    //通过ContentResolver对象查询数据
    Cursor cursor = resolver.query(Uri uri, String[] projection, String selection,
                                     String[] selectionArgs, String sortOrder);
    while (cursor.moveToNext()) {
        String address = cursor.getString(0); 
        long date = cursor.getLong(1);
        int type = cursor.getInt(2);
   }
    cursor.close();

//创建内容观察者
 private class MyObserver extends ContentObserver{
        public MyObserver(Handler handler) {
            super(handler);
        }
        //当观察到Uri代表的数据发生变化时调用此方法，程序会回调onChange()方法，
        //并在该方法中处理相关逻辑
        public void onChange(boolean selfChange) {
            super.onChange(selfChange);
          }
    }

  ContentResolver resolver = getContentResolver();
    Uri uri = Uri.parse("content://aaa.bbb.ccc");
    //注册内容观察者
    resolver.registerContentObserver(uri, true, new MyObserver(new Handler()));

@Override
protected void onDestroy() {
     super.onDestroy();
     //取消注册内容观察者
     getContentResolver().unregisterContentObserver(new MyObserver(       
                new Handler()));
}