Android基礎(chǔ)-ContentProvider

1、ContentProvider用來存儲和檢索數(shù)據(jù)ContentProvider是應(yīng)用之間互相訪問數(shù)據(jù)的唯一方法Android自身提供了一些常用的Provideraudio、video、image、contacts等如果你想使你的數(shù)據(jù)能夠共享，要么建立一個你自己的ContentProvider；要么往已存在的ContentProvider中寫數(shù)據(jù)借助工具類ContentResolver 獲得ContentResolver由activity或context的方法：getContentResolver() 使用ContentResolver的方法訪問數(shù)據(jù)庫查找：query插入：insert更新：up

2、date刪除：delete每一個Content Provider都有一個Uri來標(biāo)識它本身vider.Contacts.Phones.CONTENT_URIContent Provider存儲數(shù)據(jù)的形式：final Cursor ContentResolver.query(Uri uri, String projection, String selection, String selectionArgs, String sortOrder)使用者自行管理Cursor的生命周期final Cursor Activity.managedQuery(Uri uri, Strin

3、g projection, String selection, String selectionArgs, String sortOrder)由所在的Activity來管理Cursor的生命周期String projection = new String People._ID, People._COUNT, People.NAME, People.NUMBER ;Uri contacts = People.CONTENT_URI;Cursor managedCursor = managedQuery(contacts, projection, / Which columns to return

4、 null, / Which rows to return (all rows) null, / Selection arguments (none) / Put the results in ascending order by name People.NAME + ASC);private void getColumnData(Cursor cur) if (cur.moveToFirst() String name, phoneNumber; int nameColumn = cur.getColumnIndex(People.NAME); int phoneColumn = cur.g

5、etColumnIndex(People.NUMBER); String imagePath; do name = cur.getString(nameColumn); phoneNumber = cur.getString(phoneColumn); while (cur.moveToNext(); 增加一條新記錄：insert給一條已存在的記錄增加新信息：insert更新記錄：update刪除記錄：delete借助：ContentValues、ContentResolverContentValues values = new ContentValues();/ Add Abraham Li

6、ncoln to contacts and make him a favorite.values.put(People.NAME, Abraham Lincoln);/ 1 = the new contact is added to favorites/ 0 = the new contact is not added to favoritesvalues.put(People.STARRED, 1);Uri uri = getContentResolver().insert(People.CONTENT_URI, values);Uri phoneUri = null;phoneUri =

7、Uri.withAppendedPath(uri, People.Phones.CONTENT_DIRECTORY);values.clear();values.put(People.Phones.TYPE, People.Phones.TYPE_MOBILE);values.put(People.Phones.NUMBER, 1233214567);getContentResolver().insert(phoneUri, values);更新：ContentResolver.update()刪除：ContentResolver.delete()通過Sqlite的方式建立ContentProvider