android 应用程序数据共享ContentR…

1.实现一个ContentProvider.
public class DataProviders extends ContentProvider {
  private static final String DATABASE_NAME = "UIDB";
  private static final int DATABASE_VERSION = 1;
  private static final String TABLE_NAME = "UITable";   public static String ID = "_id";
     public static String NAME = "display_name";
    
  private static class DatabaseHelper extends SQLiteOpenHelper {
   DatabaseHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
   } @Override
   public void onCreate(SQLiteDatabase db) {
    Log.d("tag", "onCreate");
    db.execSQL("CREATE TABLE " + TABLE_NAME + " (" + ID
      + " INTEGER PRIMARY KEY AUTOINCREMENT," + NAME + " TEXT" + ");");
   } @Override
   public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    Log.d("tag", "onUpgrade");
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
             }
  }// ---------------------------------------------------------------------------------
  private DatabaseHelper mOpenHelper;@Override
  public boolean onCreate() {
   mOpenHelper = new DatabaseHelper(getContext());
   return true;
  }@Override
  public Cursor query(Uri uri, String[] projection, String selection,
    String[] selectionArgs, String sortOrder) {
   SQLiteDatabase db = mOpenHelper.getReadableDatabase();
   
   Cursor c = db.query(TABLE_NAME, projection, selection, selectionArgs, null, null,
     null);
   return c;
  }@Override
  public String getType(Uri uri) {
   return null;
  }@Override
  public Uri insert(Uri uri, ContentValues initialValues) {
   Log.d("tag", "insert");
   SQLiteDatabase db = mOpenHelper.getReadableDatabase();
   db.insert(TABLE_NAME, null, initialValues);
   return uri;
  }@Override
  public int delete(Uri uri, String where, String[] whereArgs) {
   Log.d("tag", "delete");
   SQLiteDatabase db = mOpenHelper.getReadableDatabase();
   return db.delete(TABLE_NAME, where, whereArgs);
  }@Override
  public int update(Uri uri, ContentValues values, String where,
    String[] whereArgs) {
   Log.d("tag", "update");
   
   getContext().getContentResolver().notifyChange(OServerActivity.CONTENT_URI, null);
   
   SQLiteDatabase db = mOpenHelper.getReadableDatabase();
   return db.update(TABLE_NAME, values, where, whereArgs);
  }2.Androidmanifest.xml文件中声明 
<provider android:name=".DataProviders"    
              android:authorities="org.yihu.datachanage" />可定义provider权限


 3.定义 Uri 
4.在其它程序中访问
public class ShareDateActivity extends ListActivity {
  public static final Uri CONTENT_URI = Uri.parse("content://org.yihu.datachanage");
  @Override
  public void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState); Cursor c = getContentResolver().query(CONTENT_URI, null, null,
     null, null); startManagingCursor(c);
 ListAdapter adapter = new SimpleCursorAdapter(this,
 android.R.layout.simple_list_item_2, c,
 new String[] { "_id", "display_name" },
 new int[] { android.R.id.text1, android.R.id.text2 });
 setListAdapter(adapter);
  }
 }