Android Studio - Complete Android Apps Tutorial – Content Provider - Day 18 - 8.41

Content Provider
2
 Content Provider  One of the Application Components  Used to share data usually SQLite database across applications
3
 Content Provider  Provides an abstraction from the underlying data source e.g. a SQLite database.  Provide mechanisms for defining data security e.g. by enforcing read/write permissions  Provide an interface for publishing and consuming data, based around a simple URI addressing model using the content:// schema.  Used in  Search suggestions with Quick Search Box  Data transfers with SyncAdapter
4
 Create a Content Provider  New → Other → Content Provider
5
 Create a Content Provider  URI authority string of a Content Provider is usually package_name.provider  Unique, only one provider tied to a authority string
6
 ContentProvider  Override onCreate to initialize the data source, usually for SQLite database, create an instance of SQLiteOpenHelper subclass
@Override public boolean onCreate dbHelper = new DbHelpergetContext; return true;
7
 ContentProvider  Override insert to insert a row in a SQLite database table and return a Uri
@Override public Uri insertUri uri, ContentValues values dbHelper.getWritableDatabase. insert"data", null, values; return Uri. parse "content://my.wenjiun.iotsensor.provider";
8
 ContentProvider  Override delete to delect one or more rows in a SQLite database table and return the number of rows deleted
@Override public int deleteUri uri, String selection, String[] selectionArgs int count = dbHelper.getWritableDatabase. delete"data", selection, selectionArgs; return count;
9
 ContentProvider  Override query to return a Cursor by querying a SQLite database table passing over the corresponding parameters @Override public Cursor queryUri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder Cursor cursor = dbHelper.getReadableDatabase. query"data", projection, selection, SelectionArgs, null, null, sortOrder; return cursor;
10
 ContentResolver  Call getContentResolver to obtain an instance of Content Resolver  Provides access to content providers where it accepts requests, and resolves these requests by directing these requests to the content provider with a distinct authority.  Includes the CRUD create, read, update, delete methods corresponding to the abstract methods insert, delete, query, update in the Content Provider