Simple use of ContentProvider in Android

1. New class for inheriting ContentProvider

 PackageCom.wangzhu.demo;ImportAndroid.content.ContentProvider;Importandroid.content.ContentValues;ImportAndroid.content.Context;ImportAndroid.database.Cursor;Importandroid.database.sqlite.SQLiteDatabase;ImportAndroid.net.Uri; Public classMycontentproviderextendsContentProvider {/*** ContentProvider data access Path*/     Public Static FinalUri uri = uri.parse ("Content://com.wangzhu.provider"); Privatesqlitedatabase database; @Override Public intDelete (Uri arg0, String arg1, string[] arg2) {return0; } @Override PublicString GetType (Uri arg0) {return NULL; } @Override Publicuri insert (URI uri, contentvalues values) {Database.insert ("tab", "_id", values); return NULL; } @Override Public BooleanonCreate () {database= GetContext (). Openorcreatedatabase ("Myprovider.db3", Context.mode_private,NULL); Database.execsql ("CREATE TABLE IF not EXISTS tab (_id INTEGER PRIMARY KEY autoincrement,name TEXT not NULL)"); return true; } @Override Publiccursor Query (Uri arg0, string[] arg1, String arg2, string[] arg3, string arg4) {cursor cursor = Database.query ("tab",NULL,NULL,NULL,NULL,NULL,                NULL); returncursor; } @Override Public intUpdate (Uri arg0, contentvalues arg1, String arg2, string[] arg3) {return0; }}

2. Add ContentProvider access to the application in Androidmanifest.xml

        <!--android:exported is set to true to indicate that other apps can access it, otherwise it can't be accessed-        <provider            android:name= " Mycontentprovider "            android:authorities=" Com.wangzhu.provider "            android:exported=" true ">        </provider>

3. Insert and Query

        FinalUri uri =Mycontentprovider.uri; /*** Write data to the provider*/    protected voidwrite () {//get the Contentresolver object using the Getcontentresolver () methodContentresolver resolver =Getcontentresolver (); Contentvalues Values=NULL; Values=Newcontentvalues (); Values.put ("Name", "Java"); //call the Insert method of the Contentresolver object to insert the dataResolver.insert (URI, values); Values=Newcontentvalues (); Values.put ("Name", "Swift");        Resolver.insert (URI, values); Values=Newcontentvalues (); Values.put ("Name", "Python");        Resolver.insert (URI, values); Values=Newcontentvalues (); Values.put ("Name", "C #");    Resolver.insert (URI, values); }    /*** Read the contents of the provider*/    protected voidRead () {StringBuilder Accum=NewStringBuilder (); //get the Contentresolver object using the Getcontentresolver () method//invokes the query method of the Contentresolver object, queries the data, and returns the cursor objectcursor cursor = getcontentresolver (). Query (URI,NULL,NULL,NULL,NULL);        Cursor.movetofirst ();  for(inti = 0, count = Cursor.getcount (); I < count; i++) {accum.append (cursor.getstring (Cursor.getcolumnindex ("Name")) . Append ("\ n");        Cursor.movetonext (); } System.err.println ("READ:" +Accum); }

Simple use of ContentProvider in Android