print barcode c# In the next section you will create your Content Provider in Android

Generator QR Code in Android In the next section you will create your Content Provider

In the next section you will create your Content Provider
QR Code Drawer In Visual C#
Using Barcode creation for VS .NET Control to generate, create QR Code ISO/IEC18004 image in VS .NET applications.
Quick Response Code Maker In .NET
Using Barcode generation for ASP.NET Control to generate, create QR-Code image in ASP.NET applications.
Creating Your Content Provider
Paint QR Code ISO/IEC18004 In VS .NET
Using Barcode creator for .NET framework Control to generate, create QR Code 2d barcode image in VS .NET applications.
Paint Quick Response Code In VB.NET
Using Barcode printer for Visual Studio .NET Control to generate, create Quick Response Code image in VS .NET applications.
Using Eclipse, open FriendsProviderjava, which will become the Content Provider for your project You are going to use this custom Content Provider in your Activity to retrieve data from your Friends database
Making Bar Code In Objective-C
Using Barcode generation for iPhone Control to generate, create bar code image in iPhone applications.
UPC A Drawer In .NET
Using Barcode drawer for .NET Control to generate, create UPC Code image in VS .NET applications.
Android: A Programmer s Guide
Encode Barcode In Java
Using Barcode generator for Java Control to generate, create barcode image in Java applications.
Barcode Scanner In Java
Using Barcode Control SDK for Java Control to generate, create, read, scan barcode image in Java applications.
As always, let s start by looking at the imports for this file You need to import the Friends class and several other classes:
Encode Code 128 Code Set B In Visual C#
Using Barcode generation for Visual Studio .NET Control to generate, create Code-128 image in Visual Studio .NET applications.
Scanning Data Matrix In Visual Basic .NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET applications.
import import import import import import import import import import import android_programmers_guideFindAFriendFriends; androidcontent*; androiddatabaseCursor; androiddatabaseSQLException; androiddatabasesqliteSQLiteOpenHelper; androiddatabasesqliteSQLiteDatabase; androiddatabasesqliteSQLiteQueryBuilder; androidnetUri; androidtextTextUtils; androidutilLog; javautilHashMap;
GTIN - 12 Recognizer In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
Encode Bar Code In None
Using Barcode creator for Software Control to generate, create barcode image in Software applications.
As you can see, you are importing several packages here, most of which deal with SQL I will explain these packages as you use them The package you will be using first is androidcontent To utilize and override the required methods for being a Content Provider, your FriendsProvider class needs to extend ContentProvider Take a look at the following class outline, which includes several variable definitions that you will use throughout your provider:
European Article Number 13 Generation In None
Using Barcode creator for Software Control to generate, create GS1 - 13 image in Software applications.
Bar Code Maker In None
Using Barcode maker for Software Control to generate, create barcode image in Software applications.
public class FriendsProvider extends ContentProvider { private SQLiteDatabase mDB; private static final String TAG = "FriendsProvider"; private static final String DATABASE_NAME = "friends"; private static final int DATABASE_VERSION = 2; private static HashMap<String, String> FRIENDS_PROJECTION_MAP; private static final int FRIENDS = 1; private static final int FRIENDS_ID = 2; private static final UriMatcher URL_MATCHER;}
Recognize USS-128 In Visual C#
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
Encoding Bar Code In Java
Using Barcode maker for Java Control to generate, create barcode image in Java applications.
The Content Provider contains several methods that you will want to override, including onCreate( ), query( ), insert( ), delete( ), and update( ) Because these methods will be called by Activities using your Content Provider, you must override them to specifically access the Friends database The onCreate( ) method that you will be overriding calls a SQLiteOpenHelper Therefore, before you can override the onCreate( ) method of the ContentProvider, you have to create a class that extends SQLiteOpenHelper
Make UPC - 13 In Java
Using Barcode generator for BIRT Control to generate, create EAN13 image in BIRT reports applications.
EAN128 Creation In Visual Basic .NET
Using Barcode generator for Visual Studio .NET Control to generate, create GS1-128 image in .NET framework applications.
11:
Painting Barcode In .NET Framework
Using Barcode creation for ASP.NET Control to generate, create barcode image in ASP.NET applications.
UPC-A Supplement 5 Scanner In .NET
Using Barcode reader for .NET Control to read, scan read, scan image in VS .NET applications.
Application: Find a Friend
The code block that follows is a subclass of your Content Provider that extends SQLiteOpenHelper:
private static class DatabaseHelper extends SQLiteOpenHelper { @Override public void onCreate(SQLiteDatabase db) { dbexecSQL("CREATE TABLE friends (_id INTEGER PRIMARY KEY," + "name TEXT," + "location TEXT," + "created INTEGER," + "modified INTEGER" + ");"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Logw(TAG, "Upgrading database from version " + oldVersion + "to " + newVersion + ", which will destroy all old data"); dbexecSQL("DROP TABLE IF EXISTS friends"); onCreate(db); } }
The DatabaseHelper class you just created contains two overridden methods: onCreate( ) and onUpgrade( ) The onCreate( ) method is used when creating the database from code, or in instances where the table definition does not exist
NOTE
Given that you created the database structure from the adb shell, you will not rely on the onCreate( ) method of DatabaseHelper to establish your database
With the DatabaseHelper class created, you can now override the onCreate( ) method for your Content Provider:
@Override public boolean onCreate() { DatabaseHelper dbHelper = new DatabaseHelper(); mDB = dbHelperopenDatabase(getContext(), DATABASE_NAME, null, DATABASE_VERSION); return (mDB == null) false : true; }
This is a fairly simple method that, in the end, returns a Boolean representing whether or not your database could be opened You use the SQLiteOpenHelper created in your
Android: A Programmer s Guide
sibling class to open the Friends database Notice that you pass the database name into the DatabaseHelper class If the database object mDB is not null when it returns, then the database was successfully opened and you can query it Next, override the query( ) method of the ContentProvider class This will be the meat of your Content Provider The query( ) method is called from your Activity through the Content Provider to gather the records from your database Take a look at the code in the overridden version of the query( ) method:
@Override public Cursor query(Uri url, String[] projection, String selection, String[] selectionArgs, String sort) { SQLiteQueryBuilder qb = new SQLiteQueryBuilder(); switch (URL_MATCHERmatch(url)) { case FRIENDS: qbsetTables("friends"); qbsetProjectionMap(FRIENDS_PROJECTION_MAP); break; case FRIENDS_ID: qbsetTables("friends"); qbappendWhere("_id=" + urlgetPathSegments()get(1)); break; default: throw new IllegalArgumentException("Unknown URL " + url); } String orderBy; if (TextUtilsisEmpty(sort)) { orderBy = FriendsFriendDEFAULT_SORT_ORDER; } else { orderBy = sort; } Cursor c = qbquery(mDB, projection, selection, selectionArgs, null, null, orderBy); csetNotificationUri(getContext()getContentResolver(), url); return c; }
The query( ) method does a little bit of housekeeping, by checking the validity of the database URL passed into it and defining a query sort order The URL check is to ensure that you are trying to access only the Friends database If you are attempting to access a database from another Activity, or from another Content Provider, the query( ) method throws an exception
11:
Copyright © OnBarcode.com . All rights reserved.